ogpf

Object Based Interface to GnuPlot from Fortran (ogpf)

Installation

Prerequisite: gnuplot must be installed on your system.

Zero Installation Library

The ogpf is a zero installation library! Just copy and paste the ogpf.f90 in your project folder or in your library folder and use it! No any further step is required. However if you like to add ogpf to your projects through package managers, builders, installers see below options!

<details> <summary><b>Fortran Package Manager (fpm)</b></summary>

To use ogpf with your fpm project, add the following to your package manifest file (fpm.toml):
[dependencies]
ogpf = { git = "https://github.com/kookma/ogpf.git" }
You can then use the package as normal in your Fortran program with use ogpf.

To run the example program in this package with fpm:
$ git clone https://github.com/kookma/ogpf.git
$ cd ogpf
$ fpm build
$ fpm run --example

</details>

<details> <summary><b>Meson Builder</b></summary>

The alternative is through the use of the Meson builder, which is multiplatform and multi source language build system. You can just use the ogpf git repo as a subproject in your own meson project. If you're unfamiliar with it, just read this begginer's guide.

After learning the basics, you can create a folder called subprojects on the root of your project and create a file inside with the following content:
[wrap-git]
url=https://github.com/kookma/ogpf
revision=head
Then on the meson.build file you have to import the subproject and grab the library variable. This is a sample meson.build file:
project('research','fortran')

ogpf_proj = subproject('ogpf')
ogpf_dep = ogpf_proj.get_variable('ogpf_dep')

executable('research',
   dependencies: ogpf_dep)
and all the compiler flags will be handled.

</details>

Usage

Make sure you have a working version of gnuplot must be installed on your system. Start with provideed examples.

2D Plots

Simple plot | Animation :-----------------------------:|:------------------------------------: Example 04 | Example 09

3D Plots

Surface | Contour :-----------------------------:|:------------------------------------: Example 04 | Example 09

GnuPlot Interface

Purpose:   Object Based Interface to GnuPlot from Fortran (ogpf)
Platform:  Windows XP/Vista/7/10, Linux
		   (It should work on other platforms, e.g Mac see the finalize_plot subroutine in ogpf.f90)
Language:  Fortran 2003 and 2008
Requires:  1. Fortran 2003 compiler (e.g gfortran 4.7, IVF 12.1, and later ...)
              There is only two more features needs Fortran 2008 standard
              execute_command_line and passing internal function as argument.
		   2. gnuplot 5 and higher (other previous version can be used)
Author:    Mohammad Rahmani
           Chem Eng Dep., Amirkabir Uni. of Tech
           Tehran, Ir
           url:    aut.ac.ir/m.rahmani
           github: github.com/kookma
           email:  m[dot]rahmani[at]aut[dot]ac[dot]ir
License:   MIT. Please always give a link to this repo

PLotting Capabilities

2D Plots

plot(v)
plot(x,y)
plot(x,y, linespec)
plot(x1,y1,ls1, x2,y2,ls2, x3,y3,ls3, x4,y4,ls4)
plot(x, M)
semilogx(x,y)
semilogy(x,y)
loglog(x,y)

3D Plots

surf(x,y,z)
surf(x,y,z,lspec)
surf(x,y,z, palette)
surf(z, palette)
contour(x,y,z,palette)
contour(z,palette)

Animation

animation_start(delay)
animation_show()

Multiplot

multiplot(rows, cols)

Mathematical Utility Functions

linspace(a,b,n)
linspace(a,b)
arange(a,b,dx)
meshgrid(X,Y, xgv,ygv)
meshgrid(X,Y, xgv)

Color palette

Nine different color palettes are available. See Ann Schnider gnuplot color palettes and Gnuplotting. These color palettes can be used with:

surf(x,y,z,palette='plt-name')

contour(x,y,z,palette='plt-name')

set1
set2
set3
palette1
palette2
paired
dark2
accent
jet

The ogpf library other features

There are plenty of commands to customise the plots. This includes:

Plot annotation (e.g. title, xlabel, ylabel, and zlabel)
Axes setting (e.g. xrange, yrange, zrange, and grid)

call gp%axis([-1.0,+1.0])                     ! Sets xrange
call gp%axis([-1.0,+1.0,-2.0,+2.0])           ! Sets both xrange and yrange
call gp%axis([-1.0,+1.0,-2.0,+2.0,-3.0,+3.0]) ! Sets all axis at same time

call gp%xlim([-1.0,+1.0]) ! Sets only the xrange
call gp%ylim([-2.0,+3.0]) ! Sets only the yrange
call gp%zlim([-3.0,+3.0]) ! Sets only the zrange

Line and marker color and style
Gnuplot options (e.g. fonts, tics format, frame format,... )

The ogpf options command

The option command is a very powerful command and can be used to customize the gnuplot in many ways. Options can be set by calling the ogpf options. In every call, it is possible to set several options separated by semicolon or options can be set by several calls. Below shows few samples:

Sample 1

Set the legend (key) at the right bottom of window

call gp%options('set key bottom right')

Sample 2

Define a new line style

call gp%options('set style line 1 lc rgb "blue" lt 1 lw 2 pt 6 ps 1.5')

Sample 3

Use several options each uses separate command

call gp%options('set tics')

call gp%options('set tics font ",8"') ! font size for tics

Sample 4

Set several options at the same time using semicolon as delimiter

call gp%options('unset tics; unset colorbox')

Demo

There is a collection of examples in demo.f90 to show the capabilities of ogpf.

Easy to use

To use ogpf in your project, add the library file to your fortran project (code)

ogpf.f90 (the main library)

For details see 'demo.f90'

Important Note

To use ogpf on other operating system, you may need to modify the terminal type and fonts in the section of Configuration Parameters. A Makefile has been provided to build the demo from command line.

Example codes

This section shows selected example codes from demo.f90

Example 1

    SUBROUTINE Exmp01
        !...............................................................................
        !Example 1: A very basic example
        !...............................................................................
        TYPE(gpf):: gp
        INTEGER, PARAMETER:: n=17
        Real(wp):: x(n)
        Real(wp):: y(n)
        ! Input data
        x=dble([-8,-7,-6,-5,-4,-3,-2,-1,0,1,2,3,4,5,6,7,8])
        y=dble([66,51,38,27,18,11,6,3,2,3,6,11,18,27,38,51,66])

        ! Annotation: set title, xlabel, ylabel
        CALL gp%title('Example 1. A simple xy plot')
        CALL gp%xlabel('my x axis ...')
        CALL gp%ylabel('my y axis ...')
        Call gp%options('set style data linespoints')
        !Call Plot to draw a vector against a vector of data
        CALL gp%plot(x, y)
    END SUBROUTINE Exmp01

Will produce

Example 01

Example 04

Plot several data series at the same time

    subroutine exmp04

        type(gpf):: gp
        integer, parameter:: n=50
        integer, parameter:: m=65
        real(wp):: x(n)
        real(wp):: y(n)
        real(wp):: xv(m)
        real(wp):: yv(m)
        real(wp), parameter :: pi=4.d0*atan(1.d0)
        ! Input data
        x=linspace(-pi,pi,n)  !linspace is a utility function from module ogpf
        y=sin(x)

        xv=linspace(0.d0, 2.d0*pi,m)
        yv=cos(2.d0*xv)
        !           This is the maximum number of plot can be drawn at the same time
        !           If you have more data see, you can plot can be used with matrices!
        call gp%title('Example 4. Plot four data sets using gnuplot')
        call gp%options('set key top left; set grid')

        call gp%plot(x,y, 'title "sin(x)"', &
            xv,yv, 'with lp lt 6 title "cos(2x)"', &
            xv, 2.d0*yv, 'title "2cos(2x)" lt 7', &
            xv, 0.5d0*yv, 'title "0.5cos(2x)" with points pt 8')

        ! Another example with keyboard arguments
        call gp%plot(x1=x,y1=y,x2=xv,y2=yv)

    end subroutine exmp04

Will produce

Example 04

Example 05

    SUBROUTINE Exmp05
        !...............................................................................
        ! Example 5: Use line style and legends
        !...............................................................................
        TYPE(gpf):: gplot
        INTEGER, PARAMETER:: n=50
        Real(wp):: x(n)
        Real(wp):: ys(n)
        Real(wp):: yc(n)
        Real(wp):: ysc(n)
        Real(wp), PARAMETER :: pi=4.d0*atan(1.d0)
        ! Input data
        x=linspace(-2.d0*pi,2.d0*pi,n)  !linspace is a utility function from module Utils
        ys=sin(x)
        yc=exp(-0.1d0*x)*cos(x)
        ysc=sin(x/2.d0)*cos(2.d0*x)

        ! Annotation, set title, xlabel, ylabel
        CALL gplot%title('Example 5. A sample with style and legends')
        CALL gplot%xlabel('x, rad')
        CALL gplot%ylabel('y, dimensionless')

        ! Plot to draw three set of data
        CALL gplot%plot(x,ys,'title "sin" with lines lt 5 lc rgb "#0008B0"', &
                        x,yc,'title "cos" with points lt 6 lc rgb "#FF1100"', &
                        x,ysc,'title "sin(x/2)cos(2x)" with lp lt 7 lc rgb "#00AA04"' )

    END SUBROUTINE Exmp05

Will produce

Example 05

Example 06

     subroutine exmp06

        type(gpf):: gplot

Ogpf

Install / Use

README

ogpf

Installation

Zero Installation Library

Usage

2D Plots

3D Plots

GnuPlot Interface

PLotting Capabilities

2D Plots

3D Plots

Animation

Multiplot

Mathematical Utility Functions

Color palette

The ogpf library other features

The ogpf options command

Demo

Easy to use

Important Note

Example codes