kplot_draw — plot
    data on Cairo context
#include <cairo.h>
  
  #include <kplot.h>
void
  
  kplot_draw(const struct kplot
    *p, double, w,
    double, h,
    cairo_t *cr);
The kplot_draw function draws all valid
    points of all data sources onto a Cairo context cr of
    height h and width w. It
    performs all the necessary range and domain checks to fit all data sources
    into the image. (If no points are specified, the domain and range are zero.)
    The image is laid out as described in the Drawing Model section of
    kplot(3).