/contouring

Library for drawing filled contours for 2D functions.

Primary LanguageC++Apache License 2.0Apache-2.0

Zeeman Machine potential

Contouring

This is a small C++ library for plotting contours and/or filled contours. These are contours of the Himmelblau function.

Himmelblau function

The Contouring library draws these contours by sampling the function on a coarse grid and then solving for the function on grid lines, returning a path by callback to drawing functions. The path follows a smooth curve by calling a function for bezier splines.

Splines

The principal function in this library takes quite few arguments:

extern "C" void contour(
    double (*f)(double, double), double s,
    double x0, double y0,
    double x1, double y1,
    unsigned n, unsigned m,

    void (*move_to)(double, double),
    void (*line_to)(double, double),
    void (*curve_to)(double, double, double, double, double, double),
    void (*close_path)());

The function f is being sampled in the range [x0,x1]⨯[y0,y1] on a n⨯m grid. To draw the contour four callback functions need to be given: move_to, line_to, curve_to and close_path. These functions shoud work the same as those of the same name in the Cairo drawing library.

Usage

C++

Just copy the relevant sources to your own project.

Guile

Contouring comes with an interface for the Guile programming language. To compile this interface you need guile 2, and guile-cairo.

Python

A Python interface is still in the works.

License

This work is distributed under the Apache license v2.