GNUPLOT
Interactive Graphics

GNUPLOT is an interactive plotting program.

Copies of the source code for GNUPLOT, or an executable for Windows machines, can be obtained from the official website.

GNUPLOT can do a variety of graphics functions, including plots of

• Y = F(X), where F is a formula you type in;
• (X(I),Y(I)), where X and Y are data in a file;
• 2D vector data: ( U(X,Y), V(X,Y) );
• a parametric 3D line: (X(I),Y(I),Z(I)) where X, Y and Z are data in a file.
• a parametric 3D surface Z(X(I),Y(J)) for a regular grid;
• 2D contours of a parametric surface Z(X(I),Y(J)) for a regular grid;

By the way, every time I run gnuplot, I get the obnoxious warning message

Could not find/open font when opening font "arial", using internal non-scalable font
      

export GDFONTPATH=/usr/share/fonts/liberation
export GNUPLOT_DEFAULT_GDFONT=LiberationSans-Regular
      

Licensing:

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

Languages:

GNUPLOT is available in a non-language specific version and a C version and a C++ version and a FORTRAN77 version and a FORTRAN90 version and a MATLAB version.

Related Data and Programs:

GNUFOR, a FORTRAN90 library which provides an interface to the GNUPLOT graphics library.

GNUPLOT_I, a C library which allows an executing C, C++, FORTRAN77 or FORTRAN90 program to interact with the GNUPLOT graphics program.

GNUPLOT_I_EXAMPLES, C programs which demonstrate the use of the GNUPLOT_I library for interactive runtime GNUPLOT graphics.

GNUPLOT_I_EXAMPLES, C++ programs which demonstrate the use of the GNUPLOT_I library for interactive runtime GNUPLOT graphics.

MD1, a FORTRAN90 program which carries out a molecular dynamics simulation whose output is immediately suitable for input to GNUPLOT.

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.
3. The GNUPLOT Website.

Examples and Tests:

BLAST1 illustrates the speedup of the BLAST program on 2, 4, 6 or 8 processors, for sequences of length 150.

• blast1_commands.txt, GNUPLOT commands to draw one curve (for sequences of length 150).
• blast1_data.txt, the data file;
• blast1.png, a PNG image of the plot;

BLAST5 illustrates the speedup of the BLAST program on 2, 4, 6 or 8 processors, for sequences of length 150, 300, 525, 1200 or 2358.

• blast5_commands.txt, GNUPLOT commands to draw one curve (for sequences of length 150, 300, 525, 1200 or 2358).
• blast5_data.txt, the data file;
• blast5.png, a PNG image of the plot;

BLOCKS plots some of the blocks of data in a file:

• blocks_data.txt, the data blocks file;
• blocks_commands.txt, GNUPLOT commands;
• blocks.png, a PNG image of the plot;

BOXES is an application that plots bar charts. (Sorry, GNUPLOT can't do filled in color bar charts yet!)

• boxes_data.txt, the data file;
• boxes_commands.txt, GNUPLOT commands;
• boxes.png, a PNG image of the plot;

CHECKERS draws red and black circles occupying the 8 x 8 grid of a checkerboard.

• checkers_commands.txt, GNUPLOT commands;
• checkers.png, a PNG image of the plot;

CHECKERBOARD draws a checkerboard of 64 red and black squares. It does this by specifying the location and color of each square. Note that, as far as I can tell, we have to include a bogus "plot" command that plots something in order for the 64 squares to show up. Drawing filled graphics like this is not something GNUPLOT is known for.

• checkerboard_commands.txt, GNUPLOT commands;
• checkerboard.png, a PNG image of the plot;

COLUMNS plots some of the columns of data in a file:

• columns_commands.txt, GNUPLOT commands;
• columns_data.txt, the data columns file;
• columns.png, a PNG image of the plot;

CLUSTER is a sample application that plots data in a file.

• cluster_commands.txt, GNUPLOT commands;
• cluster_data.txt, the data file;
• cluster.png, a PNG image of the plot;

FILLED_CONTOURS makes a contour plot with color between the contour lines.

• filled_contours_commands.txt, GNUPLOT commands;
• filled_contours_data.txt, the data file;
• filled_contours.png, a PNG image of the plot;

LORENZ plots sample points from a solution of the Lorenz equations.

• lorenz_commands.txt, GNUPLOT commands.
• lorenz_data.txt, the graphics data file.
• lorenz_3d.png, a 3D plot, created by gnuplot, of (X(t),Y(t),Z(t)).
• lorenz_time.png, a 2D plot, created by gnuplot, of (t,X(t)), (t,Y(t), and (t,Z(t)).

MANY_CURVES contains many columns of data. We want to plot column 1 as X, and each of columns 2 through 15 as Y, without typing 14 separate commands. The solution is to use a FOR loop!

• many_curves_commands.txt, GNUPLOT commands;
• many_curves_data.txt, the data file.
• many_curves.png, a PNG image of the plot;

MFLOPS records the logarithm base 2 of the vector size, versus the MegaFLOPS rate, for an FFT calculation run using OpenMP on 2 processors. The data shows how the MegaFLOPS rate rises steeply, levels off, and begins, perhaps, to fall.

• mflops_data.txt, the data file;
• mflops_commands.txt, GNUPLOT commands;
• mflops.png, a PNG image of the plot;

MFLOPS2 records the logarithm base 2 of the vector size, versus the MegaFLOPS rate, for an FFT calculation run using OpenMP on 1 and 2 processors. The data shows how the MegaFLOPS rate for the 1 processor program rises more quickly, but levels off sooner.

• mflops2_commands.txt, GNUPLOT commands;
• mflops2_data.txt, the data file;
• mflops2.png, a PNG image of the plot;

MIDPOINT is an illustration of the midpoint quadrature rule. Given a function, we show how the area under the curve can be approximated using 10, 20 and 40 rectanges whose height is determined by the function value at the midpoint of equally spaced subintervals

• midpoint_commands.txt, GNUPLOT commands;
• poly10.txt, function values at 10 midpoints;
• midpoint10.png, a PNG image of the plot;
• poly20.txt, function values at 20 midpoints;
• midpoint20.png, a PNG image of the plot;
• poly40.txt, function values at 40 midpoints;
• midpoint40.png, a PNG image of the plot;

P makes a contour line plot of pressure data:

• p_commands.txt, GNUPLOT commands;
• p_data.txt, the pressure data.
• p_contours.png, a PNG image of the plot;

PARAMETRIC makes a parametric plot:

• parametric_commands.txt, GNUPLOT commands;
• parametric.png, a PNG image of the plot;

POLAR makes a polar plot:

• polar_commands.txt, GNUPLOT commands;
• polar.png, a PNG image of the plot;

POWERS counts integers 1 to 10, their squares, and square roots:

• powers.txt, data.

RANGES controls the range of a plot:

• ranges_commands.txt, GNUPLOT commands;
• ranges.png, a PNG image of the plot;

SCATTER_2D makes a scatter plot of X, Y data:

• scatter_2d_commands.txt, GNUPLOT commands;
• scatter_2d_data.txt, the data;
• scatter_2d.png, a PNG image of the plot;

SCATTER_3D makes a scatter plot of X, Y, Z data (which happens to lie on a sphere).

• scatter_3d_commands.txt, GNUPLOT commands;
• scatter_3d_data.txt, the data;
• scatter_3d.png, a PNG image of the plot;

SINE_CURVE plots y=sin(x):

• sine_curve_commands.txt, GNUPLOT commands;
• sine_curve.png, a PNG image of the plot;

SPARSITY displays the sparsity pattern of a matrix before and after reordering. Notice that, because of differing conventions in (I,J) matrix indexing and (X,Y) Cartesian display, our data file is set up so that, if entry (I,J) is nonzero, we store the value (J,-I). In this way, the plot "looks" like the matrix.

• sparsity_commands.txt, GNUPLOT commands;
• sparsity_1_data.txt, the data to be plotted.
• sparsity_1.png, a PNG image of the plot;
• sparsity_2_data.txt, the data to be plotted.
• sparsity_2.png, a PNG image of the plot;

TRIANGULATION is a plot of a triangulation.

• triangulation_commands.txt, GNUPLOT commands;
• triangulation.png, a PNG image of the plot;

TWO_FILES plots data from two files together:

• two_files_commands.txt, GNUPLOT commands;
• two_files_1.txt, the first file of data;
• two_files_2.txt, the second file of data;
• two_files.png, a PNG image of the plot;

TWO_PLOTS plots two functions together:

• two_plots_commands.txt, GNUPLOT commands;
• two_plots.png, a PNG image of the plot;

UV makes a vector plot of velocity data:

• uv_commands.txt, GNUPLOT commands;
• uv_data.txt, the velocity data.
• uv_vectors.png, a PNG image of the plot;

You can go up one level to the EXAMPLES directory.