CHANGES TO THE GM-DATA-VIEWER
==========================================================================

Oct. 2002
   Added ability to view coordinate axis values when
   the range is small.

Sep. 2003
   When Gaussian noise is added, the random seed is set to the current time.


Oct./Nov. 2004
   Recompiled using the latest VC++ compiler.
   File|Open dialog box has been added where the user can enter
   the two files.  The second optional file does not have to be a .pre file.
   Code converted to double precision.
   When saving a data file, values have more significant figures.
   A warning instead of an error would be displayed when idir=0.
   There is no flicker when the window is resized.
   Zoom in/out causes window to resize automatically.
   <Esc> resets the view.
   Right-clicking on a data point displays its information on the status bar,
   and the point is hilighted.
   Magnify/shrink is also in the menu.
   Added Options|Region... option to select a region to view.
   New plotting method using GradientFill.  View|plotting method .
   Min/max values can now be changed for both plots.
   Data points are plotted as dots instead of circles. ??
   Able to plot normalized and non-normalized differences of data.

Apr. 2005
   Added ability to change plot titles:  Options | Labels...
   <SHIFT>-<Right button> causes dialog box to open displaying data
   information.  User can change error or delete the data.
   Able to display data on a log scale.

May 2005
   Can now use different colourmaps.  View | Colourmap ...

Oct. 2005
   File can be opened by double-clicking on it.
   Added banner.
   Fixed bugs -  delete data point bug and log scale view.

Feb. 2006
   When there are duplicate data points, error information is improved.
   Data can be plotted as coloured circles.  (View | plotting method | circles)
   Font size can be changed. (View | font | ...) or <Alt>-<1|2>
   Data can be downsampled.
   Data outside the current region can be removed.  ( Edit | Crop data )
   Data file can be opened in a text editor (notepad). ( File | Text editor ... )
   Can plot elevation (3rd column).
   Can plot 3-column (topography) files.
   Added 2 topography colourmaps.

Apr. 2006
   Coordinate labels can be changed.

June 2006
   Plots can be arranged vertically and horizontally. (View | arrangement ...)

Feb. 2007
   Filenames on command line should be in quotes.  This allows spaces in filenames.