A simple module for generating plots from Fortran using Python's matplotlib.pyplot.

Currently, this module can be used to generate simple plots from Fortran. Eventually, it may be expanded to provide additional features and other types of plots.

The way it works is simply to generate a Python script with the plotting code, which is then executed from the command line using the Fortran execute_command_line function.

The module requires a modern Fortran compiler (it uses various Fortran 2003/2008 features such as deferred-length strings). It should work fine with the latest gfortran or ifort compilers. A simple script build.sh is provided for building the library and test program (requires gfortran and FoBiS). It will also build the HTML documentation if FORD is installed.

• matplotlib.pyplot.plot -- 2D/3D plot of lines and/or markers
• matplotlib.pyplot.bar -- bar plot
• matplotlib.pyplot.contour -- contour plot
• matplotlib.pyplot.contourf -- filled contour plot

The following example generates a plot of the sine function:

    program test

    use,intrinsic :: iso_fortran_env, only: wp => real64
    use pyplot_module

    implicit none

    real(wp),dimension(100) :: x,sx
    type(pyplot) :: plt
    integer :: i

    !generate some data:
    x = [(real(i,wp), i=0,size(x)-1)]/5.0_wp
    sx = sin(x)

    !plot it:
    call plt%initialize(grid=.true.,xlabel='angle (rad)',&
                        title='Plot of $\sin(x)$',legend=.true.)
    call plt%add_plot(x,sx,label='$\sin(x)$',linestyle='b-o',markersize=5,linewidth=2)
    call plt%savefig('sinx.png', pyfile='sinx.py')

    end program test

• The API documentation for the current master branch can be found here. This is generated by processing the source files with FORD. Note that the build script will also generate these files automatically in the doc folder, assuming you have FORD installed.

• Matplotlib