Documentation

Documentation

fortplot is a Fortran plotting library with no external dependencies, rendering the same figure to PNG, PDF, and text.

The front page covers installing it and the plotting calls themselves. This page is the map of everything else.

API reference — modules, derived types, and procedures, generated from the source.
API compatibility — method mapping for projects moving from pyplot-fortran.
Contributor notes — release process and implementation notes.

Examples

The examples gallery shows every example with its plot, its source, and the PNG, PDF, and text output it generates. The list is generated from example/fortran/, so it is never out of step with the tree.

Backends

One figure renders to three backends, chosen by the extension passed to savefig:

Extension	Backend	Notes
`.png`	raster	Anti-aliased, self-contained PNG encoder
`.pdf`	vector	Embedded TrueType text, scalable output
`.txt`	text	Terminal-friendly; ASCII charset by default

None of these depend on an external library: the PNG encoder, the zlib compressor, the PDF writer, and the TrueType rasteriser are all part of fortplot.

Braille text mode

The text backend can render line and scatter data as Unicode braille dots for higher resolution inside each terminal cell, while axes, ticks, and labels stay plain text. Each character cell holds a 2-by-4 dot grid encoded as U+2800 + bitmask; the dot-bit layout matches Drawille (left column dots 1,2,3,7 -> 0x01,0x02,0x04,0x40; right column dots 4,5,6,8 -> 0x08,0x10,0x20,0x80).

type(figure_t) :: fig
call fig%initialize(80, 24)
call fig%set_text_charset('braille')
call fig%add_plot(x, y)
call fig%savefig('plot.txt')

Braille is opt-in: .txt output stays ASCII unless set_text_charset('braille') is called.