GPL_DISPLAY
Display Data from Gnuplot GPL Files

GPL_DISPLAY, a MATLAB library which tries to read the data in a typical gnuplot GPL file, describing a 1D, 2D or 3D curve, or a surface Z(X,Y) defined on a regular grid, a triangular grid, or an irregular quadrilateral grid, displays it in a more attractive way than gnuplot is capable of.

GNUPLOT does not do a very good job of displaying 3D surfaces. It sketches them out with lines, or some simple solid surfaces. In some cases, MATLAB can take the same data and make a much more attractive image. This set of programs tries to read a few typical GPL data files, and display them appropriately.

Licensing:

The computer code and data files made available on this web page are distributed under the GNU LGPL license.

Languages:

GPL_DISPLAY is available in a MATLAB version.

Related Data and Programs:

DEALII, examples which illustrate the use of DEAL.II, a finite element method (FEM) Differential Equations Analysis Library (DEAL), by Wolfgang Bangerth and others.

FEM2D_PLOT_GPL, a MATLAB program which reads information about nodes, elements and nodal values for a 2D finite element method (FEM) and creates a GPL file describing a surface plot of U(X,Y), which can be displayed by GNUPLOT.

GNUPLOT, MATLAB programs which illustrate how a program can write data and command files so that gnuplot can create plots of the program results.

GPL, a data directory which contains examples of GPL files, a graphics file format used by gnuplot;

gpl_display_test

Reference:

1. Philipp Janert,
   Gnuplot in Action: Understanding Data with Graphs,
   Manning, 2010,
   ISBN13: 978-1-933988-39-8,
   LC: QA276.4.J37.
2. Thomas Williams, Colin Kelley,
   gnuplot 4.4, An Interactive Plotting Program,
   The Free Software Foundation, 2010.

Source Code:

• gpl_classify.m, NOT WORKING YET, but intending to read a GPL file and figure out which kind of GPL file it is (curve, grid, patches).
• gpl_curve.m, reads a GPL file that describes a single curve with 1D, 2D or 3D data, and displays it with the Matlab plot() or plot3() command.
• gpl_dimension.m, reads a GPL file and tries to determine the "dimension" of the data.
• gpl_grid.m, reads a GPL file of (X,Y,Z(X,Y)) data for an M by N product grid, and calls Matlab's surf() command to display the data.
• gpl_squares.m, reads a GPL file of (X,Y,Z(X,Y)) data for an irregular grid of rectangles, such as used by deal.ii, and calls Matlab's patch() command to display the data as a surface.
• gpl_squares_count.m, reads a GPL file of (X,Y,Z(X,Y)) data for an irregular grid of rectangles, such as used by deal.ii, and counts the number of rectangles.
• gpl_triangles.m, reads a GPL file of (X,Y,Z(X,Y)) data for an irregular grid of triangles, and calls Matlab's patch() command to display the data.
• s_word_count.m, counts the number of words in a string.
• timestamp.m, prints the current YMDHMS date as a time stamp.