12 May, 2008
Version 2.1.6.8

• Box-and-whisker plots and dot graphs may now have a logarithmic scale. Scaling may be set programmatically with the new Stat_Scaling macro/DDE command.
   
• For XY plots, if you copy/paste a curve into the same document then the new curve's legend will be "Copy of <source legend>", or "Copy of Curve x" if the source curve has no legend entry.
   
• Increased the maximum number of reference lines from 50 to 100. (This was needed for a user plugging in many reference lines in place of grid lines at desired locations different than those chosen by DPlot. New options for grid lines will be coming soon.)
   
• Bug fix: The legend in 2D contour plots might have been clipped when saving a bitmap image and/or copying a bitmap to the Clipboard.
   
• Bug fix: An error in processing Campbell Scientific datalogger files might have resulted in overwriting another area in memory, causing later unpredictable behavior. In the last DPlot update this might have resulted in a false positive when testing for a pirated version of DPlot.
   

2 May, 2008
Version 2.1.6.7

• Probability scales may now range from 0-1 instead of the default 0-100. Among other things, this allows you to use Percent number formatting on a probability scale. Amended ProbabilityFlags macro/DDE command to take account of this option.
   
• For Bubble plots, the mouse hover tooltip gadget now shows the bubble magnitude as "Z=" in addition to the X and Y values.
   
• The maximum number of decimal places on the Number Formats dialog has been increased from 8 to 12.
   
• Slightly modified the way Scan X,Y works: if the Shift key is pressed, then clicking on the scroll bar arrows or using the arrow keys moves 10x whatever the current increment is.
   
• Increased the maximum number of plugin modules (Generate, File Import, or File Export) from 20 to 50. This will primarily be of interest to those developing their own plugins for DPlot.
   
• Added a placeholder for macro/DDE commands to specify a curve or data set by entering one or more substrings from the legend associated with that curve or data set. (See the description of the SelectCurve command.) For example [SelectCurve(LegendHas("ABC","DEF"))] will select the first curve whose legend contains both ABC and DEF. LegendHas may be used in any command in place of a curve index. If the search fails, no replacement is made (which will subsequently result in an error message when attempting to interpret LegendHas("substring") as a number). Thanks to Ian from Tata Motors for the suggestion.
   
• You may now resize a 2D plot by dragging any corner of the plot (in addition to using Specify Plot Size). When sized using this method, Specify Plot Size is turned on if not previously on. The size will be rounded to the nearest tenth inch, millimeter, or centimeter, depending on the default measurement units selected under Options>General. Dimensions might be subject to the constraints of the plot type: triangle plots will always be an equilateral triangle, Mercator projections will retain the correct shape, etc.
   
• Bug fix: Very long line segments on XY plots (made very long by zooming in or setting the plot extents to a small fraction of the data extents) might not have been clipped properly. In this release DPlot relies on its own internal clipping rather than using Windows' built-in clipping algorithm if the plot extents are less than 1/20 of the full extents of the data, in either direction.
   
• Bug fix: If "Axes only" was used for the grid type on an XY plot, in metafiles the arrowheads on the axes might have been clipped.
   
• Bug fix: The function parser (used in Y=f(X) and similar commands) might have erroneously returned a "Too many parameters" error for functions of more than two arguments in which the last argument was another function, e.g. NORMDIST(x,0,SQRT(0.2)).
   

9 April, 2008
Version 2.1.6.6

• Preference files will now include line styles, symbol styles, line widths, and symbol sizes for all curves. Previous versions only stored this data for the first 20 curves.
   
• Spin buttons throughout DPlot are now forced to the designed width. In previous versions spin button width was set to the width of a standard scrollbar (user-settable with Control Panel). This led, in some cases, to overlapping controls if you increased the scrollbar width above the default value.
   
• Looks only: DPlot now uses the look of XP-specific common controls (buttons, checkboxes, etc.) on XP and Vista. Welcome to 2003 :-)
   
• Bug fix: A saved DPlot file containing XY data might have erroneously saved the data as if the X axis had equally-spaced values if at any time the data did have a constant spacing but you then used Delete Points in Box to delete one or more values before saving the file.
   
• Bug fix: A roundoff error might have resulted in symbols being 1 pixel off on logarithmic scales. This was generally most noticeable with symbols using crossed lines.
   
• Bug fix: List Peaks might have crashed with 3D data.
   
• Bug fix: If Data points was checked on the Contour Options dialog for randomly-spaced 3D data, symbols were drawn at each point regardless of whether that point lie outside extents set with the Extents/Intervals/Size command.
   

27 March, 2008
Version 2.1.6.5

• DPlot will now correctly handle blank entries in CSV files for "quoted" values (date and time combinations, for example). In previous versions blank quoted entries were only handled correctly if represented by two consecutive quotation marks; for two consecutive delimiters (commas or tabs) in place of a quoted value, DPlot would have stopped processing the file at that point, deciding that the data type for that column didn't match the corresponding column in previous lines.
   

23 March, 2008
Version 2.1.6.4

• Corrected two problems with DPlot's FFT routine that have been present from the start: a) The first point in the FFT should be equal to any offset from zero in the input record. This value was off by a factor of 2. b) For an input number of points equal to a power of 2, the output FFT was normalized by dividing by N, when it should have been divided by N-1.
   

21 March, 2008
Version 2.1.6.3

• Bug fix: It was possible to cause an integer overflow (crashing DPlot) with the Y=f(X) and similar commands if the range in values divided by the selected interval was greater than 2^31. This problem has actually been present for years, but was made much more apparent by the recent change of dynamically showing the number of points that would be generated by the given extents and interval.
   

18 March, 2008
Version 2.1.6.2

• A change in version 2.1.6.0 to remember the Pick Columns to Plot setting caused DPlot to display the Specify Columns to Plot dialog when opening a file on the command line. In this release files opened by a command line operation will not display that dialog, regardless of whether that option was previously selected.
   
• Bug fix: If you clipped the Z extents of a 3D view using Extents/Intervals/Size and elected to draw grid lines on the surface, in rare cases an integer overflow might have caused DPlot to crash, particularly when rendering to a high resolution device like a printer.
   
• Bug fix: The Multiple option on the Print dialog might have crashed DPlot the first time you selected "Select All" due to an uninitialized data problem.
   

12 March, 2008
Version 2.1.6.1

• Bug fix: A recent change meant to improve on DPlot's default tick mark intervals might have resulted in a crash if Specify extents was checked and the lower limit was a negative value with a larger magnitude than the positive upper limit.
   
• Bug fix: Bar charts were not drawn properly to enhanced or standard metafiles if you zoomed in on the graph or set the extents of the plot to some subset of the entire data. This bug effected both metafiles copied to the Clipboard and saved files.
   
• The Y=f(X) command now presents the from X and to X values using the current number formatting for the X axis. (Previously, these values always used the default number scheme). Previous values used in this command will be displayed using more significant figures than in previous versions (Date and Time, for example, will show times down to microseconds when appropriate). And the dialog now shows the number of points that will be generated using the from X, to X, and with interval dX settings. This functionality will be added to the other curve/surface generating commands in a future release.
   

6 March, 2008
Version 2.1.6.0

• Amended the BMP, GIF, PNG, and TIF file export modules to optionally use a better color quantization routine when saving 8-bit images from displays with greater than 8-bit color depth (which, these days, is just about everybody). The default color quantization method does not work well in some cases when saving an image with a colored background. The optional method works much better but comes with a performance penalty, taking several seconds for large images (which might be important if automating this process and producing thousands of bitmaps). Modified the SetPluginImageDims macro/DDE command to include this new option.
   
• In most all dialog boxes that include lists of curves, the list entries now include a short line segment and/or symbol in the appropriate color. This change makes it a bit easier to quickly pick the desired curve from a list, particularly when the curve has no legend entry.
   
• DPlot does a better job handling calendar date number formats on 3D/4D surface plots. In previous versions these numbers were treated the same internally as all other number formats, so that it usually wasn't possible to get, for example, grid lines or tick marks at exact 1 month or 1 year intervals.
   
• Expanded the list of built-in date formats in the Number Formats dialog from 7 to 24 of the most commonly used formats. As before, you may select a format from the list or enter your own format.
   
• Added an option to not draw an inverted scale on the opposite side of the plot from a probability scale. The default is to draw that inverted scale. Added ProbabilityFlags macro/DDE command to set these options.
   
• Improved on version 2.1.5.5's change in the behavior of the Force circular plots option for polar plots. In version 2.1.5.5 the size was set to roughly 80% of the minimum of the document window width and height. This worked well for most display sizes, but not larger resolutions (unless you used very large fonts). In this version DPlot will use all available display space.
   
• The "Pick columns to plot" option for CSV and other multi-column text files is now turned on by default, and your choice for that option will be preserved. In previous versions this option was always initially turned off.
   
• Bug fix: If Outline solid symbols was checked, then symbols from the Wingdings 2 font were drawn in black.

27 February, 2008
Version 2.1.5.9

• Bug fix: Additional problems (this time with 3D plots and bubble charts) that resulted in draining GDI resources have been fixed. These problems generally were not apparent until several thousand plots were created in the same DPlot session. Thanks again to Sven Henze for the assist in tracking these bugs down.

18 February, 2008
Version 2.1.5.8

• Bug fix: An obscure problem was introduced in version 2.1.5.6 that resulted in strange problems (toolbar bitmaps disappearing, all lines being drawn with a single-pixel black line, and other assorted weirdness) after saving several thousand bitmap images. Thanks to Sven Henze for the assist in tracking this down.

17 February, 2008
Version 2.1.5.7

• You can now specify the background color of the entire plot, the legend, text notations and point labels. Past versions always used the Windows' window background color. Added new BkColor macro/DDE command and modified the LegendParams, TextNoteEx, TextNote3D, TextPointLabel and TextPointLabel3D macro/DDE commands to take this new capability into account.
   
• Bug fix: Retrieving a DPLOT_PLOTMETRICS structure with DPlot_GetBitmapEx or DPlot_GetPlotMetrics was broken in version 2.1.5.6.
   
• Bug fix: If you did not install the Excel Add-In, the uninstall program for DPlot might have produced an Excel runtime error and then shut down.
   

10 February, 2008
Version 2.1.5.6

• Changed the behavior of the image export plugins (BMP, GIF, TIF, etc.) to make better use of the resolution setting. In past versions this setting was only used to set the resolution field in the image header for formats that supported it (TIF in particular) and otherwise had no effect on the contents of the image. The result was that in most cases the images saved with the plugins were essentially screenshots. In this version if the resolution entry is non-zero then font sizes, line weights, and plot dimensions will be scaled up by resolution/(screen resolution). So if, for example, you have specified the plot size using the Extents/Intervals/Size menu command, then the box around the plot will be (size in inches) * resolution pixels. This change may require you to pay a bit more attention to the image width and size entries. If you use 0 for either the width or height of the image and do not specify the plot size with Extents/Intervals/Size, then the output image will be the document window size times resolution/(screen resolution). For a maximized document window this might easily result in an Insufficient memory error when attempting to create the image. For best results with a non-zero resolution, always check the Specify size option under Extents/Intervals/Size.
   
• Added /sp command line switch for preference files. If /sp is used, the specified preference file will be processed for all new documents during the current session, much as %APPDATA%\DPlot\Preferences\default.set is used in all previous versions. The /s command line switch continues to work as in all previous versions: the preferences file will only be used with files specified on the command line.
   
• Bug fix: In the last several versions of DPlot if you entered a non-positive value for an extent with a logarithmic scale using the Extents/Intervals/Size menu command, DPlot would present the appropriate error message, but then crash.
   
• Bug fix: DPlot considered the size and position of text notes when finding the extents of metafiles, whether the text note was hidden or not. This might have resulted in unnecessary white space if a note was placed outside the extents of a graph and then hidden.
   
• Bug fix: On an XY plot with only 1 curve whose X values were not monotonically increasing, the Smooth command proceeded as if everything was in order but produced no new curve (nor any error message). In this version the Smooth command will present an error message and suggest using the Sort command on the Edit menu.
   
• Bug fix: For 3D views of 3D or 4D data, setting the line widths of the major or minor axis lines to a negative number should have resulted in those lines not being drawn. And it does, unless Antialias objects on display output is checked (General command on the Options menu). In this update those lines will not be drawn, regardless of whether antialiasing is used or not.
   

27 January, 2008

• Excel Add-In only: The Add-In has handled time-of-day values poorly from the beginning, chiefly because DPlot expects "Time of Day" numbers to be in hours, while in Excel times are fractional days. Past versions of the Add-In examined the format used for numbers, and if the format included time formatting but no date format, used "Time of Day" format and multiplied the appropriate columns by 24. This worked mostly fine as long as the input values were only times. But if the values included dates (not shown in Excel only because of the selected format option), the displayed times in DPlot were correct, but the underlying data was all fouled up with calendar dates multiplied by 24. This made it all but impossible to add reference lines at the correct location, set the extents to the proper values, etc. In this update to the Add-In, "Time of Day" format will never be selected. Instead, "Date and Time" format is selected and the date formatting string is set to "<none>". The updated Add-In is now included with the version 2.1.5.5 update. If you have already installed version 2.1.5.5 then you can get the Add-In update here.
   

25 January, 2008
Version 2.1.5.5

• Changed the behavior of the Force circular plots option for polar plots. In previous versions the plot size was simply set to 6x6 inches, if the size had not previously been specified. Six inches on many display monitors is a bit small. In this version if the size has not been specified then it is set to roughly 80% of the minimum of the document window width and height. As in previous versions, this size may be changed with the Extents/Intervals/Size command on the Options menu. If you do change the size using that command DPlot will force the width and height to the smaller of those values.
   
• Modified the Playback feature to use the specified line widths to draw curves, rather than forcing the line width to a single pixel as was done in all previous versions for performance reasons. Performance has not suddenly improved, though, and for multiple data sets you'll have better luck setting the line widths to 0 (a single pixel) before using Playback.
   
• Expanded the ColumnsAre macro/DDE command to include support for 3D text files, and the ability to specify which columns to plot.
   
• Bug fix: When attempting to save a bitmap image (BMP, GIF, PNG, etc.) with a FileSaveAs command, if the document window was not maximized and the DPlot application window was minimized, DPlot crashed. This was due to DPlot being confused about whether it was drawing to a bitmap for the display window or for a saved image. Thanks Sven Henze for the help in isolating this problem.
   
• Added "Version" as a valid XTYP_REQUEST item. Version number is returned. To use Version in an XTYP_REQUEST from Microsoft Excel, for example, you can type "=DPlot|System!Version" in a blank cell. If using DPLOTLIB.DLL, the DPlot_GetVersion function is preferable as that function distinguishes between the version of DPlot and DPlot Jr that will be started by a call to DPlot_Start or other functions that launch DPlot, and DPlot_GetVersion doesn't require either DPlot or DPlot Jr to be running.
   
• Added "LastCurveFit" as a valid XTYP_REQUEST item. The curve fit equation last produced by the Polynomial Curve Fit menu command or CurveFit macro/DDE command is returned, formatted identically to the text shown on the Curve Fit Coefficients dialog box.
   
• Bug fix: The Z3=f(Z1,Z2) command might have resulted in a crash if you had zoomed in on the Z1 surface at the time you ran that command.
   

20 January, 2008
Version 2.1.5.4

• The ERF function is more accurate for small (< 1.E-7) values. ERF is used internally by the CDF, NORMDISTCDF, and NORMINV functions. Previous versions used a polynomial approximation that gave very accurate answers for x >> 1.E-7, but does not work well for smaller values. This version uses the Maclaurin series erf(x) = 2/sqrt(pi) * (x - x^3/3 + x^5/10 - x^7/42 + x^9/216 + ...) for x < 1. This series converges very quickly for small x and takes about 15 iterations for x near 1.
   
• The NORMINV function had a similar but different problem for x < 5.E-7. NORMINV(x,0,1) is now very accurate for x > 1.E-14.
   
• Bug fix: The Check for Updates feature on the Help menu did not work properly for university subscribers in the third year of a 3-year subscription.
   
• Bug fix: For point labels containing $YMAX, $YMIN, and similar shortcuts, DPlot confused that shortcut with $Y (the value at the referenced point). This generally resulted in the wrong label text, which might have grown longer each time the plot was redrawn for any reason.
   

12 January, 2008
Version 2.1.5.3

• Continued with version 2.1.5.1's changes to how Wingding symbols are handled. Most (though not all) characters with a hollow interior will now be filled with the window background color.
   
• Data processing mode now allows a choice of time units. Previous versions were limited to milliseconds.
   
• Added "Assume input dates are of the form d/m/y" option to the General Options dialog. If unchecked DPlot behaves as in all previous versions: dates from text boxes, the clipboard, or a file are assumed to be in the order m/d/y unless one of the first 2 fields is greater than 1000, if the assumed date field is greater than 12, or if any of the fields is non-numeric, e.g. "Feb". If this option is checked, dates are assumed to be in the order d/m/y unless, again, one of the above conditions is matched.
   
• For bar charts with amplitude or percentage labels, if "Labels outside bars" is checked then the labels will be drawn with a transparent background. In previous versions the labels were opaque.
   
• Bug fix: On XY plots with "Grid Lines or Box" set to "Axes Only" and "Arrowheads" turned off, an uninitialized data problem might have caused DPlot to crash when copying a plot to the clipboard.
   
• Bug fix: With acceleration plots in data processing mode it was not possible to use the right-click menu to change the line style, symbol parameters, or color of the velocity or displacement plots.
   

4 January, 2008
Version 2.1.5.1

• Amended the way that the new Wingding symbol capability is implemented. For many characters with hollow interiors (primarily round, square, or diamond-shaped glyphs), DPlot will now first draw another solid character with the same shape but using the window background color so that the interiors of these symbols are opaque.
   
• Changed the ZGrid function in the Excel Add-In such that if the Y rows and X columns are evenly-spaced, the data is passed to DPlot as points on a rectangular grid rather than random 3D points. The latter plot type is generally superior for the same data because the rendering is not so dependent on how the mesh is divided into triangles.
   
• Bug fix: The Generate Mesh menu command sometimes had serious (as in crashing) problems with very rough/random data.
   
• Bug fix: Recent change to the DPlot_AddData function allowing a NULL pointer for X was poorly implemented and might have fouled up with all calls for XY plots, with or without a NULL X.
   

1 January, 2008
Version 2.1.5.0

• Added Mercator Projection scaling for XY plots.
   
• Added ArcView Shapefile file import plugin.
   
• Symbols, symbols, and more symbols. Two symbols have been added to the 38 previously available graphic symbols, and you may now use characters from the Wingdings, Wingdings 2, or Wingdings 3 fonts (assuming those fonts are installed).
   
• If Fill Between Curves is used to fill in the area formed by closing the first curve (in other words, the 2nd curve is set to "None"), then DPlot now checks against Y values lying outside limits set with Amplitude Limits and breaks the fill up into multiple segments if necessary. This is particularly useful for filling in, for example, maps imported with the ArcView Shapefile plugin. (In the example, the boundary of Alaska is one continuous curve.)
   
• Polar charts may now have a reversed amplitude axis, with the maximum value at the center of the plot. This may be handy for (for example), global maps.
   
• Added a wireframe option to 3D plots.
   
• Text notations may now be oriented vertically.
   
• Vector plots may now be drawn w/o an arrowhead by setting the arrow height to 0. (In previous versions a 0 arrow height forced the default height of 0.15"). Also added an option to center vectors on the data point; the default is to draw vectors with the tail at the point.
   
• Added $SUMX and $SUMY text shortcuts for XY plots, which will be replaced with the sum of all X/Y coordinates for the given curve when a plot is drawn.
   
• Added PMT function to the function parser, for use in Y=f(X) and similar commands. This function returns the payment for a loan based on constant payments and a constant interest rate.
   
• In previous versions for tripartite plots the displacement grid lines and labels were drawn in a single pass, followed by the acceleration grid lines and labels. This resulted in acceleration grid lines overwriting displacement labels (which might not have been noticeable with thin grid lines and/or a small font). In this version grid lines are drawn in both directions, followed by labels for both directions.
   
• Added "Use settings for current plot" option to the Excel Add-In. If checked and a new plot produced by the Add-In is of the same type as the currently active plot in DPlot (XY, 3D, etc.), then preferences from the active plot (line styles, colors, etc.) will be used in the new plot.
   
• Bug fix: Recent change of allowing point-click addition of new data points in an empty plot caused a crash due to the extents being uninitialized if a logarithmic scale was used on either the X or Y axis.
   
• Bug fix: Previous versions under Windows 2000 might have crashed when using the Search feature in the Help file. In this release the Help works identically to Windows 95 and 98, by launching KEYHH to display Help rather than relying on the Windows API. Search now causes no problems, but context-sensitive help within dialog boxes has been disabled. Context-sensitive help remains in place for Windows XP and Vista.
   
• Bug fix: Corrected a couple of problems with the Reorder Curves feature: In previous versions bubble plot source curves and vector angle and magnitude source curves were omitted from the list. This made it less than obvious where a curve would end up in the order of all curves. DPlot also now correctly transfers all bubble plot and vector plot settings with a curve as you move it up or down in the list.
   
• Amended the behavior of the DPlot_AddData function. For XY plots if the *array1 argument (the address of an X array) is NULL, then X values will be generated within DPlot, with the value equal to the 0-based index of each point.
   
• Added SavePreferences macro/DDE command.
   

9 December, 2007
Version 2.1.4.9

• Bug fix: DPlot allowed metafiles larger than 32767 units wide or tall (about 12.9 inches). The maximum addressable coordinate in a metafile is 32767, so this resulted in these files being clipped in the target application.
   
• Bug fix: The function parser (used by the Y=f(X) and similar commands) might have returned a value smaller than the minimum allowable magnitude for a double precision float: 2^-1022, or about 2.2251E-308. Internally this caused no problems; these values were simply truncated to 0 if used in any further calculations. But if these values were saved to a DPlot file or other ASCII text file and then re-read by DPlot, the result was generally a crash.
   

16 November, 2007
Version 2.1.4.8

• Bug fix: The "fix" for enhanced metafiles in version 2.1.4.0 contained an uninitiliazed data problem that might have caused DPlot to crash when saving an EMF file.
   

7 November, 2007
Version 2.1.4.7

• Modified the Find intersections command to better handle calendar dates and other large magnitude values. In previous versions DPlot threw out an intersection if it was determined to be more-or-less equal to a previously-found intersection. A precision problem in that check resulted in false positives for large values on either axis with relatively small differences between intersections on that same axis. For example if the difference on the X axis was a few seconds on a date scale then the new intersection would often be discarded, assuming the difference in Y was also small or zero.
   

5 November, 2007
Version 2.1.4.6

• Interpretation of file type 'C' (number of points and time step followed by data with one or more values per row) is now more flexible. These files may contain up to 3 header lines; if present those lines will be used for the plot title. The number of points and interval values may be on the same or different lines.
   

27 October, 2007
Version 2.1.4.5

• Added several options for bubble plots. You may now specify whether solid symbols should be outlined in black or not (in previous versions, they always were). And instead of automatically using the minimum and maximum amplitudes of the bubble source curve, you can 1) enter custom extents that the low and high bubble size and color should be mapped to and 2) specify whether amplitudes outside those limits should be drawn with the limit values or not drawn at all. Amended Bubbles macro/DDE command to take account of these new capabilities.
   
• One final change related to Campbell Scientific datalogger files. If the column heading for the second column in the file is "RECORD", indicating a 0-based record number (a line count, in other words), that column is ignored by default. If you want to show the record number you can do so by checking the "Pick columns to plot" box. Also tightened up the determination of whether a multiple-column text file is a Campbell Scientific datalogger file: in addition to previous checks, this version checks that the first seven characters in the file are "T0A5",.
   

26 October, 2007
Version 2.1.4.4

• It is now easier to create an XY plot from scratch using the Edit Data menu command. For a new plot, the graph will be drawn with extents of +1 in both X and Y. Since the graph is now drawn for this case, you can immediately begin adding points with Ctrl+left click on the graph. In previous versions the graph was not drawn for new plots, so the only way to enter new data was by using the text boxes. Added zoom and pan buttons to increase/decrease the graph extents or shift the extents left/right/up/down - so you are now able to enter all points for a new curve using the mouse only.
   
• Yet one more change related to Campbell Scientific datalogger files: Legend entries are built from the 2nd and 3rd lines, separated by a comma. Previous version used the 2nd line only.
   
• Changed the behavior of the DPlot_Stop function. In previous versions, DPlot_Stop would shut down DPlot if there were no open documents containing data or if DPlot was hidden. This worked well for single applications interacting with DPlot, since its being hidden was a good indication that it was the calling application that started it up in that state. It did not work well, though, if two or more applications were both interacting with DPlot; one program closing it down prematurely might have interfered with the other program. In this version of DPLOTLIB.DLL, DPlot_Stop will only close DPlot if there are no open documents containing data.
   
• Bug fix: It was possible to get DPlot confused about which plots were associated with which DDE conversations, particularly when sending data to DPlot at a small time interval (in a real or simulated real-time application, for example.)
   

24 October, 2007
Version 2.1.4.3

• Two more changes to the interpretation of multiple column text files, again to accommodate Campbell Scientific datalogger files and possibly others: 1) If a non-quoted data entry contains the characters "nan", "NAN", or "NaN", DPlot interprets this as a "not a number" error and the value is considered numeric, but is skipped over. This change will properly handle Campbell files containing the error indicator "-1.#QNAN". In previous versions the error code would have been considered a text label, not a number. In turn this might have caused DPlot to reset its search for the start of the data, depending on whether a valid numeric entry was found in the same column in previous or subsequent lines. 2) For Campbell Scientific datalogger files, the first and second title lines are taken from the second and third quoted strings in the first line of the file.
   
• For polar plots, point labels will be drawn unless the bounding rectangle for the label is completely outside an imaginary rectangle surrounding the plot. This differs a bit from other scale types, for which the label will not be drawn if the reference point of the label (left side, middle) of the label is outside that box.
   
• Reference lines may now be added to polar plots.
   
• Bug fix: Recent change allowing you to split the date and time into 2 separate lines for calendar date formatting was also applied to point labels, but was not handled well. In this version point labels containing a date and time will display those values on the same line.
   
• Bug fix: DPlot would not register a hit on the same mouse-activated point label twice in a row. That is, once a mouse-activated point label was dismissed by moving the mouse, that same label would not be activated again until and unless another mouse-activated label was activated/dismissed.
   

23 October, 2007
Version 2.1.4.2

• Changed the interpretation of multiple column text files a bit so that Campbell Scientific datalogger files are handled properly. In particular, DPlot will now handle quoted date/time groups with the date in the form yyyy-mm-dd. In previous versions this group would have been considered a text label, not a date.
   
• Bug fix: The "Pick Columns to Plot" dialog didn't set tabstops properly in all cases, so columns were not properly aligned with column headings.
   
• Bug fix: Reference line locations were saved to DPlot files with only 6 significant figures. For most applications this was sufficient; for date/time scales this resulted in unacceptable roundoff errors.
   

18 October, 2007
Version 2.1.4.0

• Changed DPLOT_PLOTMETRICS structure to use double-precision data, and improved method of transferring that data to DPLOTLIB.DLL (previous versions sent this data as text; this version sends binary data. So there won't be any loss of precision). This change is primarily useful for plots with date and time values on the X axis, or any other number format with large numbers and a relatively small difference between the minimum and maximum values. This change requires DPLOTLIB.DLL version 2.1.0.6 or later and this or a later version of DPlot or DPlot Jr.
   
• Eliminated problems in enhanced metafiles with text overlapping legend boundaries, improper subscript and superscript placement, and other text sizing problems. Enhanced metafiles should also be drawn with the correct dimensions in all Office products (assuming the picture will fit within the margins.) Enhanced metafiles produced by previous versions of DPlot were typically much larger in size than the DPlot-specified dimensions, particularly in Excel and PowerPoint.
   

2 October, 2007
Version 2.1.3.8

• The GetPreferences macro/DDE command now supports a replaceable |DOCNAME| parameter. If found, |DOCNAME| will be replaced with the document title, minus any file extension if present.
   
• Added "Automatically read preference file based on filename" checkbox to Options>General. If checked, then when opening a data file for a new document, DPlot will check for a preferences file with the same filename and extension of ".set", first in the folder where the data file resides, then in the default preferences folder. If found, that preferences file will be processed. This might be a handy option if you have data files which frequently change, but you don't want to go through the same formatting steps each time you open that file.
   
• Bug fix: Several years ago DPlot was brought into line with Microsoft's recommendations for file locations. This was important on XP with limited privileges, and critical on Vista. To accommodate users of older DPlot versions, at startup DPlot copies many files from the DPlot installation folder to %APPDATA%\DPlot (c:\Documents and Settings\<username>\Application Data\DPlot on Windows 2000 and XP, c:\Users\<username>\AppData\Roaming\DPlot on Windows Vista). However, the "if it ain't broke, don't fix it" rule was ignored: if DPlot was installed to %APPDATA%\DPlot, then "old" files were deleted. This effected all versions of DPlot, but resulted in a critical problem for the licensed version: license information stored in dplot.ini was deleted at startup, so that licensed users would be prompted for their registration number every time they ran the program.
   

29 September, 2007
Version 2.1.3.7

• Bug fix: DPlot Jr only. At startup DPlot Jr displayed the error message "One or more components of DPlot Jr are missing. Please reinstall.", then quit. The error was due to an otherwise harmless change in the Help file.
   

28 September, 2007
Version 2.1.3.6

• Added printable User Manual (PDF format).
   
• Constants specified on the Y=f(X), X=f(T), Y=g(T), Y=f(X,Y1,Y2,...), and Z=f(X,Y) commands may now be used in equations within the text boxes for the from, to, and interval entries. In previous versions constants were only recognized in the text boxes for the main equation(s).
   
• Added Set X:Y=1:1 button on the Extents/Intervals/Size dialog for linear X, linear Y plots. This button is disabled unless both Specify Extents and Specify Size are checked. When pushed, the size of the plot is adjusted such that the physical scale of the X and Y values are equal: 1 unit in X will be the same length as 1 unit in Y. This action is not persistent: if you subsequently edit either the extents or the size then this relationship will no longer be true until you push the button again.
   
• Added an option to set the maximum number of points per curve for which antialiasing will be performed on XY plots. This might be useful for users who occasionally plot large data sets (for which antialiasing isn't appropriate) but who like the antialiasing option for smaller data sets. The default value of 5000 points generally works well.
   
• Added "Snap mouse" checkbox to the Edit Mode dialog for XY plots. If checked, the coordinates of the point selected with the mouse will be rounded to "nicer" values: one tenth the tick mark interval on linear scales, for example.
   
• For tripartite plots, the status bar and tooltip-like popup windows now show the values on the 45° and 135° axes as well as X and Y.
   
• For Degrees, Minutes and Degrees, Minutes, Seconds number formats, if the "Fixed number" of decimal places is checked and the number of decimal places is 1, then 0 values for minutes (and seconds for D,M,S number format) are always shown. If the number of decimal places is 2 or greater, then the minutes and seconds values will be padded with a leading 0 for values between 0 and 9, inclusive. In previous versions 0's were not displayed.
   
• For Time of Day and Elapsed Time number formats on the X axis, DPlot now does a better job of picking a default tick mark interval. In previous versions intervals like 2.5 hours were common. In this release if the extents are greater than 15 minutes and less than 2 days, the default interval will be one of 5, 10, 15, or 30 minutes, or 1 or 2 hours.
   
• Added an option to split the date and time used with the Calendar or Date and Time number formats into two lines, with the time displayed below the date. Added corresponding SplitDateTime macro/DDE command. This feature currently works well only on linear scales.
   
• A couple of changes were made to better handle Time of Day number format for the X extents on the Extents/Intervals/Size dialog. On entry, if the difference in extents is 24 hours or greater then the times are presented using the default number format rather than time formatting. If the extents are less than 24 hours and on exit the upper extent is less than or equal to the lower extent, 24 hours is added to the upper extent. (So, for example, 12:00PM to 8:00AM will be interpreted as noon through 8AM the next morning.)
   
• Contour Options dialog checks to see if any changes have been made when clicking OK, and does not redraw the plot unless the answer is affirmative. This will save a bit of time with very large (millions of points) data sets.
   
• Distance from command on the View menu automatically turns on the crosshair cursor, and when done turns it off if it was not previously on.
   
• You can now add/edit point labels for 3D surface plots using the Edit Mode feature, as you've always been able to do with XY plots.
   
• Improved antialiasing for line segments less than 2 pixels long for line widths of 2-5 pixels. Previous version produced stray pixels in this circumstance. Antialiasing still doesn't work especially well with very short line segments, but this version is a definite improvement.
   
• Bug fix: In dialog boxes allowing dates, times, and equations in text boxes for numeric entries, DPlot only recognized entries as times if the text contained a colon, e.g. 12:00AM. "12AM" was erroneously interpreted as an equation, which DPlot would balk at with a confusing error message concerning a lack of an operator.
   
• Bug fix: For vector plots, the angles and magnitudes Y values were considered when finding default plot extents ("Specify extents" not used). This version properly ignores those data sets when finding default extents.
   
• Bug fix: In the "Specify Columns to Plot" dialogs there was a problem with column alignment when adjacent date and time columns were combined into a single date and time value.
   
• Bug fix: Contour intervals were saved to DPlot files with only 4 significant figures. So if your surface plot had Z values ranging from, for example, 99.999 to 100, both the low and high value would be written as 100. Upon rereading the file DPlot would then force the intervals to 99 and 101.
   
• Bug fix: Corrected a previously untrapped divide by zero error when calculating standard error in List Peaks and List Peaks in Box. Thank you, Jon Canale.
   
• Bug fix: A roundoff error with Fractions number format in isolated cases caused whole numbers to be off by 1, e.g. 3.0 might have been displayed as 4.
   
• Added Repaint DDE command. This command is only useful in applications that force DPlot to draw output to a window owned by the application, using SetOutputWindow.
   
• Added C, C#, VB, and VB.NET demo programs to the DPlot Jr distribution illustrating the SetOutputWindow command. This command directs DPlot to render a graph to some window other than the normal DPlot document window, without requiring the calling application to keep track of and/or render bitmaps or metafiles produced by DPlot.
   
• If DPlot is already running when another application calls DPlot_Start with a non-zero Hide argument, DPlot (or DPlot Jr) will now be hidden if there are no open documents. In previous versions DPlot would remain visible under the same circumstances.
   

14 August, 2007
Version 2.1.3.2

• Improved antialiasing of lines, introduced in version 2.1.3.1. Antialiased line segments will have a smoother appearance in this version. Also fixed a problem with joins for segments with dx>dy in one segment, dy>dx in the other. Finally, grid line type for tripartite plots was ignored in the previous version; if antialiasing was used then grid lines were solid.
   
• Bug fix: If antialiased symbols were used, the line weight used for the symbols was not changed when editing the line width for the curve; only when changing symbols or symbol heights.
   
• Bug fix: Curve selection list boxes were broken for plots that did not use a legend, but did use curve labels (label drawn adjacent to the end of each curve).
   
• Bug fix: CTEST2 demo program distributed with DPlot Jr was a bit fouled up due to testing code not removed before distribution. The command launching DPlot in a hidden state was commented out, so that any interaction with DPlot would cause it to become visible and topmost.
   

12 August, 2007
Version 2.1.3.1

• Added 2D vector plots. Added corresponding VectorPlot and VectorPlotOptions macro/DDE commands.
   
• First cut at antialiased lines. If the (now renamed) "Antialias objects on display output" option on the Options>General dialog is selected then these items (in addition to symbols) are antialiased (display monitor and bitmap images only, not printed output or metafiles):
  • line segments and arrowheads for vector plots, point labels, etc.
  • coordinate axes for 3D views of 3D plots
  • grid lines on 3D views of 3D points on a rectangular grid
  • waterfall plots
  • coordinate axes of triangle plots
  • radial and circular grid lines and outer border of polar plots
  • displacement and acceleration lines on tripartite grids
  • and finally, curves on XY plots and contour lines on 2D views of surface plots.
  Please note that this feature is a big performance hit on large data sets (10's of thousands of points), and can take 10x as long to render as the same plot without antialiasing. Primarily for that reason this option is turned off by default with new installations of DPlot.
  Antialiasing works best for line segments that are several line widths long or longer, and doesn't work well at all for 1-pixel long segments.
   
• ZGrid Add-In command now correctly handles blank cells. In previous versions blank cells were interpreted as Z=0.
   
• Added atan2 function to function parser (used by Y=f(X) and similar commands.)
   
• Display of Calendar date number format is more consistent. In previous versions, if the date format was set to "<none>" then the time was displayed on the corresponding axis, but within point labels and popup coordinate windows the label was blank. In this version point labels and popup windows will display the time, given those same settings.
   
• Amplitude Limits command now works with bar charts in addition to other XY plot types.
   
• Bug fix: Arrowheads on the coordinate axes for grid type=Axes only were drawn in the wrong color... unless that color was black :-)
   
• Bug fix: ClipY and EditDecimate macro/DDE commands ignored any previous SelectCurve command, always operating on all curves.
   
• Bug fix: For output to the display or to a copied or saved bitmap, X and Y axis labels on horizontal bar charts were not oriented correctly unless the document window was maximized.
   
• Bug fix: The curve indices for fill regions were not updated properly when a curve was erased. So if, for example, a fill area used curve #3 for one boundary and you erased curve #2, the fill area would then use what was previously curve #4 for the boundary.
   
• Bug fix: Fill regions created with the Fill Between Curves command were not clipped to the plot extents correctly in standard and enhanced metafiles.
   
• Bug fix: As with the Remove Random Spikes command, fixed in 2.1.2.8, several other commands correctly did not list hidden curves, but did not take omitted curves into account when retrieving curve indices to operate on. For example if the 2nd curve was hidden and you selected curve 3 to operate on, the operation would be performed on curve 2 rather than curve 3.
   
• Bug fix: Smooth command might have crashed if you clicked the Cancel button.
   
• Bug fix: Smooth command did nothing if the X values of a selected curve did not have a constant spacing. Since this command uses an FFT, it is designed to operate on curves with a constant spacing. But this should not be a strict requirement, and that requirement has been removed.
   

19 July, 2007
Version 2.1.2.8

• Another attempt (this one successful), at eliminating the "The system DLL user32.dll was relocated in memory..." error message associated with Windows XP SP2.
   
• Added Balanced Friedlander equation to the More curve fits plugin. This is very similar to the Friedlander equation, with the exception that the normalized time is modified with an exponent. This change allows the equation to model the negative phase of a pressure-time history.
   
• Hidden curves (View>Hide curves) are no longer included in the results of the List Peaks or List Peaks in Range commands.
   
• Added SetFilename DDE command. This command allows you to set the default filename of a graph produced programmatically. It does not save a file. The specified filename may be overridden by the user if/when the user saves the file.
   
• Bug fix: The Remove Random Spikes command correctly did not list hidden curves, but did not take omitted curves into account when retrieving curve indices to operate on. For example if the 2nd curve was hidden and you selected curve 3 to operate on, the operation would be performed on curve 2 rather than curve 3.
   
• Bug fix: The function parser did not properly trap overflow errors for the exp function. Arguments larger than about 709.78 caused DPlot to crash.
   
• Bug fix: Added many traps for math errors (overflow, division by 0, etc.) to the More curve fits plugin. These were generally a problem when trying to fit an ill-suited equation form to the input data, e.g. X raised to a power for input that oscillated around Y=0.
   
• Bug fix: On XY plots with two Y axes and different number formatting options on those axes, DPlot used the number format for the left axis to show Y values associated with the right axis for mouse position on the status bar, popup "tooltip" windows showing coordinates of the point under the mouse, and in the Scan X,Y dialog.
   
• Bug fix: On XY plots with multiple Y axes, the second Y label was truncated if longer than the label for the primary Y axis. This bug was introduced with the inclusion of horizontal bar charts in version 2.1.2.5.
   

7 July, 2007
Version 2.1.2.6

• The "fix" in version 2.1.2.5 to get around the "The system DLL user32.dll was relocated in memory..." error message caused more problems than it solved, and was removed. If you are running Windows XP SP2 and get this error message when starting DPlot, when trying to run or edit a macro, or if you get no error message when attempting to run a macro but the macro doesn't run, you can read more about the problem and the solution in our user forums here.
   

6 July, 2007
Version 2.1.2.5

• Horizontal bar charts. Right-click on a bar chart and select Bar Chart Options, or select the Bar Chart Options command under Linear/Log Scaling on the Options menu.
   
• Added a workaround to eliminate the "The system DLL user32.dll was relocated in memory..." error message associated with a faulty Windows XP update. Although Microsoft later published a "hotfix" for this problem, the fix was never made a part of MS's automatic updates unless the user's system had one of the handful of known (by Microsoft) applications that exhibited this problem. The actual list of programs with this problem was several orders of magnitude larger than what MS apparently ever realized.
   
• Changed how minor tick mark lengths are handled on log scales. In previous versions, the minor tick length was only used for non-integers times some power of 10, e.g. 11, 12, 13, etc. between 10 and 20. Those tick marks were only drawn if "Minor grid/tick divisions" on the Extents/Intervals/Size dialog was set greater than 1. In this version, if "Minor grid/tick divisions" is 1 then the minor tick mark length is used for all tick marks other than 1 times a power of 10 (2,3,4, etc.)
   
• Invert X and Invert Y options on Extents/Intervals/Size dialog are now enabled for bar charts, as is the InvertAxis macro/DDE command.
   
• Added Make Triangular Mesh command to Options menu for 3D surface plots of points on a rectangular grid. This command might be useful if the rectangular grid is not fully populated and/or you want to add, move, or delete specific points. (A rectangular grid with missing edge values will have stair-stepped edges, while the equivalent triangular mesh will always be convex.)
   
• Changed dotted line pattern such that the pattern starts with a solid dot (actually more of a dash) instead of whitespace. This will be mostly noticeable in a legend which uses a variety of line styles: all line segments will appear to be left-aligned.
   
• Added a filename parameter to the FilePrint macro/DDE command. If specified and the output is to a file (rather than an actual printer) then this filename will be used for the output. If omitted, then the document title is used to create the filename as in previous versions. This might be a handy option when saving one or more unnamed graphs to PDF files using one of the virtual PDF printer drivers, for example.
   
• Modified curve selection list boxes and popup tooltips for XY plots to show the curve index as well as the legend. This might be helpful when working with graphs containing many curves with similar legend entries.
   
• Time values using Time of Day or Date and Time number formats can now be displayed in any time increment down to the nearest microsecond (e.g. h:mm:ss.000000). Previous versions were limited to hundredths of seconds and additional 0's were simply displayed as 0's.
   
• For XY plots, when saving CSV or tab-separated text files, if either of the calendar date or time number formats are used for the X axis then the appropriate date and/or time is written to the file for X rather than the corresponding Excel serial number (date, date and time) or decimal time. For calendar dates, time values will be written if any X value is not a whole number. For all times, DPlot examines the first several points to determine whether fractional seconds (as small as microseconds) should be stored. Dates will be written using the format code M/d/yyyy; times will use H:mm:ss with 0 to 6 decimal places for seconds.
   
• Reference lines in 1D plots now have the same capabilities as those for XY plots. (Limit of 50; previously limited to 2. Label can go in the legend or be centered on the line.)
   
• Added Reorder groups command to the View menu for 1D plots. This is equivalent to the Reorder curves command for XY plots.
   
• Added Legend command to the Text menu for 1D plots, allowing you to specify the location and various attributes of the legend.
   
• Alignment code in LegendParams command now works correctly with 1D as well as XY plots.
   
• Bug fix: An uninitialized data problem might have caused the List Peaks in Box function to crash under some circumstances.
   
• Bug fix: X,Y Labels were sometimes clipped when copying a plot to the clipboard.
   
• Bug fix: The Operate on X and Operate on Y commands on the Edit menu resulted in the transformation also being applied to constant X and Y reference lines, respectively, when the transformation was not applied to all curves. In this release the operation is used on reference lines only when all curves are operated on.
   
• Bug fix: Uninstalling DPlot now correctly removes the Excel Add-In from Excel's Add-in collection.
   
• Bug fix: Subtract Mean command on the Edit menu might have entered an endless loop. After a single pass, on paper the new mean value should be 0. For large data sets that is rarely the case, though. So DPlot looped through the operation until the new mean value was smaller than some arbitrary small number... which unfortunately was too small in some cases. This version will exit the loop after several passes, regardless of whether the updated mean is "small enough"
   
• Bug fix: Text shortcuts used in equations that resulted in two consecutive minus signs (e.g. Y-$MEAN where $MEAN is negative) caused a crash in the function parser.
   
• Bug fix: Z-table file import plugin did not properly handle trailing spaces.
   
• Bug fix: Starting with version 2.0.7.1 DPlot calculates a root mean square (RMS) value for each curve in an XY plot. If the number of points in a curve was 0, this calculation resulted in a divide by 0 error and a crash. This error should only effect programmers using XY or XYXY commands; the only way to create a curve with 0 points is by using a SelectCurve command followed by XY or XYXY in which the selected curve index was greater than the current number of curves plus 1.
   
• Bug fix: Under some circumstances, graphs created with a series of XY or XYXY commands that were subsequently saved as DPlot files would erroneously be marked as having a constant spacing in X.
   
• Bug fix: With 2D contour plots of points on a rectangular grid, if you used a custom contour palette with only one color then DPlot erroneously applied the "cycling levels" logic and, in some cases, did not draw any contour lines. In this version the contour levels are assumed to cycle only if more than one color is used, which was the original intent of that feature.
   
• Bug fix: Recent addition of custom contour intervals might have caused DPlot to crash after performing any operation that might have modified the Z extents (Edit>Operate on Z, for example).
   
• Bug fix: Variables used in equations in text placeholders, e.g. "$=(100*$YMAX)" did not work properly if thousands separators were used or if the decimal separator was anything other than ".". In this release, if a label includes an equation ($=), then all variables in that label will use the default number format with no thousands separator and the normal English decimal point.
   
• Bug fix: Edit Data command might have resulted in overwriting data for the 2nd or subsequent curves if you added points such that the current maximum number of points was exceeded.
   
• Bug fix: Starting with version 2.1.1.5 DPlot crops most white space from bitmap images by default. This change was intended only for images saved to disk, but was unfortunately extended to images retrieved via DPLOTLIB.DLL, with no way to turn that feature off. This caused those images to no longer be placed as expected and also broke the ability to translate mouse position to data space. In this version image cropping for images retrieved by DDE functions is turned off by default, and can be turned on with [SetImageCrop(1)].
   

16 May, 2007
Version 2.1.1.9

• When interpreting command strings, either via macros or calls to DPLOTLIB functions, DPlot is now more forgiving of extra spaces in commands, and also gives more meaningful error messages for unmatched parentheses and/or brackets.
   
• Added NORMDISTCDF (cumulative distribution function, equivalent to the integral of the NORMDIST function from negative infinity to x) and NORMINV (inverse of NORMDISTCDF) functions.
   
• Added support for embedded equations and other text shortcuts to point labels.
   
• Reworked how rectangles are drawn in standard and enhanced metafiles. There will be fewer roundoff problems resulting in, for example, grid lines or tick marks being drawn just outside the plot extents. And with enhanced metafiles all rectangles will now have sharp, square corners.
   
• Reference lines are saved to preference files.
   
• Bug fix: The Swap X,Y command on the Edit menu did not swap the X,Y coordinates of point labels. This might have resulted in a crash if either (but not both) of the X or Y axes used a probability scale.
   

26 April, 2007
Version 2.1.1.8

• Added GCD (greatest common divisor), LCM (least common multiple), FPOWER (raise a number to a fractional power), ROUND (round a number to a specified number of places), and MROUND (round a number to a multiple of another number) functions to the equation parser, for use in Y=f(X) and similar commands. FPOWER is particularly useful for finding exponents of negative numbers (which would give invalid argument errors with the ^ operator).
   
• Bug fix: Fractions number formatting sometimes resulted in a fraction of 1/1.
   
• Bug fix: More curve fits command sometimes added a spurious character to the end of the legend string for the fitted data.
   
• Bug fix: A recent change to the code that converts mouse position to data values for display on the status bar might have caused a crash with very large numbers.
   
• Bug fix: An uninitialized data problem might have caused the FilePrintMultiple macro/DDE command to fail with an "Error processing this command" for no good reason.
   

6 April, 2007
Version 2.1.1.6

• Bug fix: Recent change allowing arrows with text notations did not properly save arrow information to DPlot files.
   
• Bug fix: Last update's change using temp files for reallocating arrays under low memory conditions did not properly delete the temp file when done with it.
   

3 April, 2007
Version 2.1.1.5

• You can now have both horizontal and vertical error bars assigned to the same curve.
   
• For 2D views of zoomed plots you can now restrict the pan direction to horizontal, vertical, or 45 degrees by pressing the Shift key as you drag the mouse. Also improved pan feature in general by eliminating roundoff errors that sometimes caused the plot extents to drift even though the drag direction might have been perfectly horizontal or vertical.
   
• Improved data entry in dialog boxes for Degrees, minutes and Degrees, minutes, seconds number formats. The value 30°24'36" may be entered as 30d 24m 36s or 30d 24' 36", with or without the spaces.
   
• Added right-click menu commands to select line widths and symbol sizes for XY plots.
   
• Added "For grid lines, use independent tick marks for dependent scales" checkbox on the Multiple Axes dialog. If unchecked, the values on a dependent scale will be drawn at the grid lines as in all previous versions. If checked, values on a dependent scale will be drawn at "nice" intervals, with added tick marks.
   
• Added "X values consisting of times are always sequential" checkbox to the General Options dialog. If checked, time values read from a text file or the clipboard are assumed to be in chronological order; in other words the X axis will never wrap back to the start. If unchecked, midnight is always 0, noon is always 12, etc. Added a similar option to the Options command in the Excel Add-In.
   
• Moving the cursor across a 2D view of a 3D surface plot now results in the same formatted display of the values at the cursor that you get with XY plots.
   
• Added Set client area command to the View menu. This allows you to set the size of a document window minus the sizing border and caption area. This feature is primarily useful for sizing a plot such that when saved to a bitmap format (BMP, GIF, JPG, PNG, and/or TIF), the image will be identical to what is shown on the display and be exactly the size specified.
   
• For bitmap image export (BMP, GIF, JPG, PNG, and TIF formats), added an option to specify whether white space should be cropped from the image. If checked, the image will have a 10-pixel white space border. If unchecked, the image will use the specified dimensions, with no cropping. Added equivalent SetImageCrop macro/DDE command. In previous versions cropping was automatically performed if the width or height was set to 0 (indicating that the document window dimensions should be used) and never performed if non-zero values for width and height were set.
   
• Added $YFIRST and $YLAST text placeholders. For XY plots these are replaced by, respectively, the first and last Y values in the corresponding curve.
   
• Improved performance under low memory conditions in some circumstances. When existing X,Y arrays were insufficient to add data to an existing plot or read a file in which the number of points was not initially known, DPlot would always keep (if only temporarily) the original data in memory when attempting to allocate larger arrays (then copy the original data to the new arrays). With very large data sets this was prone to out-of-memory errors. In this release, DPlot attempts to do the same, but if it fails then the original data is written to a temporary file on your hard disk and the memory used to store that data is freed. After successfully allocating the new arrays the original data is restored from that temporary file. This is of course much slower than keeping the old data in memory, but might in some circumstances allow up to 2x as many points as previous versions.
   
• Bug fix: For XY plots, DPlot_AddData or DPlot_AddData8 might have caused DPlot to crash if the array sizes for the specified document were not large enough to accommodate the incoming data.
   
• Bug fix: Copy Data and Insert Link did not work properly for 4D surface or scatter plots and in some cases caused DPlot to crash.
   
• Bug fix: New feature in Pick columns to plot dialog boxes for handling multi-line column headings did not handle parsing the headings well when the columns were space-delimited.
   
• Bug fix: Uninitialized data problems might have caused Equal Intervals and Operate on Y (for 3D data) menu commands to crash.
   
• Bug fix: Using text placeholders (e.g. $YMAX) in equations worked properly only using the default number format for the axis corresponding to the placeholder. Other formats might have resulted in wrong answers (dates, for example, which can be interpreted as another equation) or invalid syntax errors (e.g. PI fractions).
   
• Bug fix: Reordering curves using the Reorder curves menu command or the Move Up/Down right-click menu commands on the legend did not recalculate or shift text shortcut values (e.g. $YMAX, $AREA) along with the data. So text shortcuts would reference the incorrect curves after moving a curve up or down in the order.
   
• Bug fix: For multiple independent linear Y scales, the panning feature (drag the mouse or use the arrow keys on a zoomed plot) did not work well for the second Y axis unless the range in Y values was close or identical to the range in Y values on the primary axis.
   
• Bug fix: Recent change allowing input of line widths in points, millimeters, or centimeters exposed a precision problem that in some cases might have made a saved DPlot file unreadable by DPlot.
   

20 February, 2007
Version 2.1.0.5

• Subscript/superscript proportion is a bit larger and easier to read. In previous versions subscripts and superscripts used 2/3 the height of the base font. In this version the ratio is 3/4.
   
• For XY plots added right-click menu entries for symbol size and line width.
   
• Added "X values consisting of times are always sequential" option to the General Options dialog. This setting affects time values read from text files or the clipboard and is on by default. If unchecked, then times are considered to be in random order and will be assigned values between 0 (midnight) and 24 (this is the behavior in all previous versions). If checked, time values are considered to be in chronological order and will have 24 hours added every time the value passes through midnight. Made a similar change to the Excel Add-In Options dialog.
   
• Bug fix: Starting with version 2.1 all Help files distributed with DPlot are CHM files (HTML Help). On Windows 95 and ME systems, and possibly Windows 98, calling the function to display those files caused a crash in DPlot. In this version, on all pre-Windows 2000 systems DPlot will launch a separate process to display the CHM files. Most of the Help functionality is intact; a noted exception is the popup windows in dialog boxes resulting from clicking on the question mark button on the title bar, then clicking on a control. That functionality is removed on pre-2000 systems.
   
• Bug fix: Last version's change to the fraction number format introduced a couple of bugs related to negative fractions.
   

15 February, 2007
Version 2.1.0.4

• Added Fractions, no reduction number format. This is identical to Fractions with the exception that the fraction will not be reduced to its simplest form. For example if the tick mark interval is 1/32 and a tick mark is at 6/32, Fractions would display the value as 3/16, while Fractions, no reduction will display the value as 6/32. Another change related to both fraction number formats is that the denominator is no longer limited to powers of 2. The denominator from the list 2,3,4,5,6,8,10,12,15,16,20,24,25,30,32,40,50,60,64 that gives the smallest error will be used. Also rearranged the number format list into functional groups, as the list was growing into an unmanageable mess.
   
• XY plot feature of panning a zoomed plot with the keyboard arrow keys or clicking and dragging the mouse now also works with 2D views of 3D or 4D surface plots.
   
• For 3D views of surface plots for points on a rectangular grid, this version allows you to set the X or Y extents to values outside the extents of the data.
   
• Added "Overwrite existing surface" checkbox to the Z=f(X,Y) dialog box. If checked, the existing surface is replaced with the new function. If unchecked, a new document is created (as in all previous versions). This might be a handy option when doing parameter studies and you have a graph formatted exactly as you like; all format settings will be preserved.
   

11 February, 2007
Version 2.1.0.3

• Added /d command line switch to set the default folder for opening and saving files. This is primarily useful for running macros from the command line when you don't want to manually edit the macro to include a default folder. See How do I specify options on the DPlot command line? in the online manual.
   
• Added control for color of planes used for the "Draw Sides" option of 3D/4D surface plots. Edges of planes will be drawn using the border color. Previous versions always used black-edged white planes. Plane color will also use light settings (Phong, Gouraud).
   
• Added controls to specify the line weights used for the coordinate axes in 3D/4D surface and scatter plots.
   
• Added buttons to both "Label Points" dialog boxes to copy current label attributes to all labels. This is handy if you have hundreds of labels.
   
• If you select millimeters as the default units on the General Options dialog, then millimeters will now be used as the default in all cases. Previous versions used centimeters in this case for large measurements (plot size, for example).
   
• "Prompt to save changed plots" is ignored if DPlot is hidden.
   
• Added DPlot_GetPlotMetrics command to DPLOTLIB.DLL.
   
• Added SetOutputWindow DDE command. When sending instructions to DPlot from another program, this command tells DPlot to render a graph to a window you specify, rather than the normal document window. This is useful primarily for real time applications.
   
• All functions in the Excel AddIn now preserve the current working directory before changing the directory to the AddIn folder (necessary to allow Excel to find dplotlib.dll) and restore the previous working directory before exiting.
   
• Bug fix: Text shortcuts (e.g. $MEAN) in equations were broken because of a few changes made to accommodate the new SUM function.
   
• Bug fix: Linear scaling routine was amended in version 2.1.0.2 in an effort to prevent 0 values from overlapping each other when "Axes at 0" was used. However, the steps taken should only have been taken when "Axes only" was used for the axis type. The result was that 0 values would never be drawn if "Axes at 0" was checked.
   
• Bug fix: Recent change adding support for HTML format on the Clipboard did not work properly when the clipboard contained both unsupported HTML (no table) and text format. In this case DPlot would erroneously report "No text is available from clipboard."
   

3 February, 2007
Version 2.1.0.2

• Added Crop command to the Edit menu for XY plots and 3D/4D surface plots. This command allows you to delete all data points that lie outside a rectangle you define with the mouse.
   
• Added FunctionOfXY1Y2 macro/DDE command for XY plots. This performs the same function as the Y=f(X,Y1,Y2,...) command on the Generate menu.
   
• Added SUM function to the equation parser used by Y=f(X) and similar commands. This is useful for evaluating, for example, Taylor series.
   
• Added several capabilities to the Fill Between Curves command: 1) You can now fill the area between a curve and any edge of the graph. Previous versions were limited to the bottom edge. 2) Added "Draw only the intersections of all areas" checkbox. If checked and more than one fill area is selected, only the overlapping region of all areas will be drawn. This feature is particularly useful for graphing the solution to systems of inequalities. For examples, see the new Graphing Inequalities and Graphing Systems of Inequalities pages.
   
• The Specify Columns to Plot dialog boxes have been given a facelift. In particular long column headings are handled better.
   
• Many commands on the Edit menu for XY plots will now allow you to operate on multiple curves in one operation. In previous versions the operation was only performed on a single curve. Affected commands include Average Points, Welch Depopulation Scheme, Skip Points, Smooth, and Equal Intervals.
   
• For 3D views of 3D/4D plots added a Z coordinate for notations that are placed in data space (as opposed to plot space). For all plot types, added the ability to draw a line with or without an arrow from a note to a point. Added new TextNote3D and TextNoteLeader macro/DDE commands and added optional arguments to the TextNoteEx macro/DDE command to handle these new capabilities.
   
• Added ClipY macro/DDE command for XY plots. This performs the same function as the Clip Y command on the Edit menu.
   
• Pressing the SHIFT key while zooming forces the zoom rectangle to be square.
   
• Logarithmic scaling routine does a better job of preventing overcrowding among the labels on the X axis.
   
• Roundoff errors in logarithmic scaling routines might have resulted in grid lines and/or curves overlapping the border around a graph by one pixel.
   
• Bug fix: Double-clicking on a curve to select it within a multiple-selection list box (e.g. with the "Operate on Y" command) did not work properly and in some cases might have caused DPlot to crash.
   
• Bug fix: Elapsed time number format ignored the time format string set on the Number Formats dialog, always using hh:mm:ss. This version uses either hh:mm or hh:mm:ss.
   
• Added DPlot_YFromX function to DPLOTLIB.DLL. This allows you to retrieve an interpolated Y value from a specified curve of a document produced by your program.
   

January 16, 2007
Version 2.1.0.1

• Bug fix: The Scan X,Y command might have erroneously reported "The curve is not visible! Zoom out to scan." for curves that did not have monotonically increasing or decreasing X values.
   
• Bug fix: X,Y Labels anchored to values outside the extents of the graph might still have been drawn.
   
• Bug fix: In preparation for allowing more than 2 Y axes in the next release, the Multiple Y axes feature with Y2=f(Y1) was unfortunately broken.
   
• Bug fix: New feature in version 2.1 of allowing up to 200 characters in the title lines and axis labels and a 4th title line was implemented only for XY plots. In this update the new capabilities work for all plot types.
   

January 12, 2007
Version 2.1.0.0

• Added the ability to specify unequal contour intervals for all 3D and 4D plots, which might be useful if there is a large range between the minimum and maximum amplitudes. Added corresponding ContourCustomLevels macro/DDE command.
   
• Added bar chart options to 1) omit the black border on filled bars, 2) draw borders around the extremes only (rather than each entire bar) and 3) draw solid bars with pseudo-3D shading. For examples see the new Bar Chart page.
   
• Title lines and axis labels are now limited to 200 characters each. Previous limit was 80 characters. Also added a fourth title line. For DPLOTLIB.DLL users and plugin authors, this change requires the new version 4 of the DPLOT structure, defined in the respective header files for the DPLOTLIB projects and in the Help file for plugins. Old programs will continue to work with version 2 or 3 of the DPLOT structure. If you want to use these new capabilities, all that is needed is to recompile your application including the new header file for your development environment. Note that if you do use the new structure, the end user must have version 2.1 or later of DPlot or DPlot Jr.
   
• Added "X,Y,Z Labels" command to the Text menu for all 3D/4D plots. This command has the same functionality as the "X,Y Labels" command for XY plots.
   
• Added right-click and double-click editing features for "X,Y Labels"
   
• DPlot will now check for and prefer HTML clipboard format for tables over plain text format. The principal difference with this change is that column headings are more likely to be interpreted correctly, particularly when copying data from tables on a web page or from a HTML Help file. In previous versions, plain text tables with column headings that included spaces or commas would not be handled correctly unless the columns were separated by tabs or delineated by "quotation marks". If the source application exports HTML format to the clipboard, this is no longer an issue since each column heading is in a separate table cell. Applications that export HTML format include Microsoft Word, Microsoft Excel, HTML Help (.CHM) files, and the most popular browsers. (Thanks to the good folks at the Help & Manual forums for their assistance with this. If you write your own Help files, you should give Help & Manual serious consideration. Their support is not beatable.)
   
• Ported old WinHelp Help file to HtmlHelp format (CHM), in preparation for Windows Vista. (Vista throws out support for WinHelp.) Again, Help & Manual to the rescue, making the translation of a going-on-20-years-old Help file to a new format relatively painless. An online Help manual has also been created with Help & Manual. The new DPlot installation program does not delete the old help files (DPLOT.HLP and CONTEXT.HLP) in case... you know... you want to cherish them for a while longer :-). Those 2 files may be safely deleted and are also removed automatically if you uninstall an old version. Help files for all plugin modules and the Excel Add-In have also been converted to HtmlHelp format.
   
• Added Scatter Plot command to Options menu, to hopefully once and for all eliminate "How do I make a scatter plot?" e-mails :-)
   
• DPlot now correctly interprets commas as thousand's separators in text files and text (and new for this version, HTML) on the clipboard.
   
• On XY plots if the primary Y axis crosses Y=0 and Specify extents is not used, then the extents of an independent second Y axis will be adjusted such that the 0's line up.
   
• Error bars at or near the edge of a plot are no longer clipped in the direction perpendicular to the error amplitude. In other words vertical error bars will not be clipped at the left or right edges of the plot; horizontal error bars will not be clipped at the top or bottom sides.
   
• For output to all devices or image types other than standard metafiles, error bars now have a cleaner appearance with squared-off end caps.
   
• Added Moving Average plugin command to the Generate menu for XY plots.
   
• Added Backbone Curve plugin command to the Generate menu for XY plots. This function creates a new curve consisting of the points with maximum Y value within a user-specified interval in X.
   
• If the number format for the X axis is "None", DPlot will now check to see if any "X,Y Labels" are on the lower X axis and have a 0 offset. If so, then the font height is taken into account when placing the title of the X axis. In previous versions the X axis title most likely would have overlapped those labels.
   
• Excel Add-In installation is now handled entirely within the setup program, so there will be no more scary warnings from Excel concerning the security risks of running a macro embedded in a worksheet.
   
• For Y=f(X) and similar commands, memory reallocation is handled more gracefully. In previous versions if the current maximum number of curves for a document was a large number and you attempted to generate a curve with a large number of points, DPlot attempted to keep that same maximum number of curves with the new max. number of points/curve. This often resulted in a confusing error message concerning insufficient memory. In this version the maximum number of curves is decreased to what is actually needed (current number of curves plus one).
   
• DPlot has always hogged the cursor during zoom and other mouse-related operations. If you switched tasks in mid-operation the cursor was still clipped to a bounding rectangle defined by DPlot (in Windows XP), and switching back to DPlot usually resulted in the screen not being repainted, with the system waiting for you to complete a mouse operation. In this version DPlot is better-behaved and aborts the current mouse operation if you switch tasks.
   
• Amended the NumberFormat macro/DDE command to include optional arguments for setting the number of decimal places to display, whether to use a thousands's separator or not, and control the label orientation.
   
• Maximum number of reference lines (Options>Reference lines) has been increased from 20 to 50. Added an option to the Reference lines menu command to draw labels centered on the reference line rather than in the legend. Modified RefLine macro/DDE command to take this new feature into account.
   
• You may now abort a running macro by pressing the <Escape> key.
   
• On XY plots with one of the calendar date number formats on the X axis, DPlot does a better job of honoring user-specified extents. In previous versions there were several situations in which DPlot would force the extents to be multiples of the tick mark interval.
   
• Bug fix: Saved bitmap images (BMP, GIF, JPG, PNG, TIF) with a specified height and width of 0 (indicating that the displayed graph dimensions should be used) included an excess amount of white space at the top of the image if the graph did not include any title lines.
   
• Bug fix: Saved bitmap images (BMP, GIF, JPG, PNG, TIF) and bitmap images copied to the clipboard were incorrectly clipped if the specified size was greater than the maximum display dimensions.
   
• Bug fix: Insert new data points at intersections feature of the Find Intersections command in some circumstances did not resize the data arrays properly when needed, with the result that the intersection point(s) might overwrite data points in some other curve.
   
• Bug fix: Undo feature did not work properly with point labels when deleting or reordering curves.
   
• Bug fix: Histogram command's "Filled bars" option did not work. This was a side effect of the recent edition allowing fill patterns in bar charts (as opposed to either hollow or solid only).
   
• Bug fix: Histogram command crashed if you specified a bin size greater than the range in amplitudes in the input (meaning only 1 bar would be produced).
   
• Bug fix: Zoom information saved to a DPlot file was handled improperly when reading that same file if the graph included multiple Y axes. This might have resulted in DPlot hanging up in an endless loop.
   
• Bug fix: Last point in a bubble plot was not drawn. Also, under some circumstances DPlot ignored bubble plot parameters when reading a saved bubble plot.
   
• Bug fix: For 4D data, the "Always auto-adjust scale factors on 3D plots" feature used the 4th dimension's extents rather than the Z dimension extents when determining the Z scale factor. This might have resulted in an exceptionally skinny, tall plot or an almost flat plot.
   
• Bug fix: A couple of problems with saving 4D data to a DPlot file might have resulted in a crash.
   

December 2, 2006
Version 2.0.7.6

• Added Bubble plots (XY plot with a third dimension mapped to symbol size and/or symbol color). Added corresponding Bubbles macro/DDE command.
   
• Added Operate on X and Operate on Y commands to the Edit menu for 3D and 4D surface and scatter plots.
   
• Improved the Define Boundary command for 3D surfaces. In previous versions small roundoff problems might have caused triangles inside the border to be deleted, and/or triangles outside the border to be retained.
   
• For triangle plots, numbers along the X and Z axis are now rotated to make it more clear which grid lines are referenced by a particular axis. Added "Clockwise" option (by default the numbers along each axis increase in a counterclockwise direction around the plot.)
   
• Saving a graph as a DPlot file now results in that filename being added to the MRU (most recently used) list. Previously only opened files were added to the list.
   
• Bug fix: DPlot ignored the "Scatter plot" setting on the Open dialog for 4D data, always producing a surface plot.
   
• Bug fix: Saving a 4D surface or scatter plot to a CSV file did not work properly, and in some cases might have crashed.
   
• Bug fix: Menues for new 4D plots did not work properly with DPlot Jr or DPlot Viewer.