The (plotutils plot) library contains drawing primitives.
There are two important types to note: <plotter> and
<plparams>. Roughly speaking, <plparams> describes the
surface on which you are drawing – its size and format – and
<plotter> describes the state of the virtual pen being used to
draw on that surface.
This procedure returns a newly allocated <plparams> in a default
state.
This procedure modifies the state of a <plparams> object. Both
parameter and value are strings. For the available parameters
and values See Plotter parameters.
To make a new <plotter> which is on object that keeps the state
of the “pen” being used to draw on a surface, use the procedure newpl.
Creates a new <plotter> object. type is the output format
that will result from this plotting: one of “X”, “png”, “svg”,
“pcl”, “gif”, or “pnm”. Other options may be present depending on
how libplot was compiled in the upstrem GNU Plotutils library.
outp and errp should be Guile output ports. outp will receive the output produced by the plotter in the format specified by type. errp will receive error messages.
param is an object of type <plparams> that has set up the
“paper” upon which we are drawing.