XPaint Files

geg, a GTK+ Equation Grapher
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geg is a simple little program that will draw 2-dimensional mathematical functions within a nice user interface. eg. f(x) = 3 + sin(x/2)
geg is an acronym for GTK+ Equation Grapher.

It was started by David Bryant <daveb@acres.com.au> in 1998, as a GTK1 program. The program has now been ported to GTK2 (and hopefully soon enough, GTK3), and several important features have been added along the way. Especially geg can now be used as a basic scientific calculator.

version 2.0.9
[ Jean-Pierre Demailly ]
* Left button is now used to activate all functions through a popup menu
  on the drawing canvas
* Scroll wheel is used to perform zoom in and zoom out, and right
  button is used to translate the origin of coordinates
* Finding curve intersections and axes intersections had been disabled
  as a result of a few buggy lines added in 2.0.8. This is now corrected

version 2.0.8
[ Jean-Pierre Demailly ]
* Derivation and integration can now be iterated

version 2.0.7
[ Jean-Pierre Demailly ]
* Normal law cumulated distribution function phi(x) introduced
* Numerical integration via 5-point Gauss-Legendre method
* A few further bugs have been corrected

version 2.0.6
[ Jean-Pierre Demailly ]
* geg now has a mode dedicated to representing discrete sequences.
* geg-2.0.6 includes the possibility of introducing user defined
  functions, computing numerically their derivatives and tangents.
* Almost all parameters are now accessible by suitable hooks in
  the symbolic formalism, and can thus be set from the calculation 
  sheets. Linewith and color of curves can be set in this way, as
  well as the size and color of tangents. The coord() function 
  has been deprecated. See the help file for details.
* The coordinate grid can be drawn or hidden
* The package incorporates several examples of calculation sheets.
* Many substantial bugs have been ironed out.

version 2.0.5
[ Jean-Pierre Demailly ]
* geg can now open and save *.geg files reproducing all calculations
  entered in sequence via the bottom command line. They can be used
  to store a given arrangement of curves along with the selected
  colors and scaling parameters.
* A new coord() function has been introduced to switch the cartesian/
  polar/parametric modes programmatically in a sequence of function calls.

version 2.0.4
[ Jean-Pierre Demailly ]
* Fixed some minor issues in radio buttons (GTK bug due to deprecation ?)
* Slight improvement in GUI presentation

version 2.0.3
[ Jean-Pierre Demailly ]
* All preferences are now configurable, including colors
* Builtin parameters can be recovered from the GUI
* Zoom functions now have orthonormal mode

version 2.0.2

[ Jean-Pierre Demailly ]
* Improved behavior of event reporting in log window
* Increased width of log window and text entries

version 2.0.1

[ Jean-Pierre Demailly ]
* Polar mode added: t-->r(t)
* Equation solver added
* external utilities can now be set through preference GUI
* various fixes (some issues were causing occasional segfaults ...)
* help system fixed and localized

version 2.0.0

[ Jean-Pierre Demailly ]
* Printing can be made either through PDF or SVG
* Parametric mode added: t-->(x,y)
* Formula parser enhanced: variables a-z can now be used as parameters
* Log window behavior fixed
* Port to GTK2 thanks to the work of Barry deFreese

version 1.0.2

[David Bryant]
* Fixed precedence of '-' (thanks to Torsten Landschoff)
* Added manpage (ditto)

version 1.0.1

[David Bryant]
* Fixed infinite configure bug that occured with recent versions of GTK+
* Fixed precedence level of '^' operator (thanks to Kris Jurka)
* Fixed cursor sizes of zoom/function intercepts/axis intercepts cursors