[R] plotting many line segments in different colors

Marc Schwartz MSchwartz at MedAnalytics.com
Fri Jul 2 23:44:33 CEST 2004

On Fri, 2004-07-02 at 16:33, rif wrote:
> I want to plot a large number of line segments, with a color
> associated with each line segment (I'm actually plotting a function of
> the edges of a 2d graph, and I want to use color to indicate the level
> of the function.)  I originally thought I could use lines, but lines
> puts all its lines in one color (from help(lines), "col: color to use.
> This can be vector of length greater than one, but only the first
> value will be used.").
> Is there a function that does what I want?  Right now I'm using the
> obvious solution of calling lines in a loop with a single segment, but
> this is really quite slow for my purposes, as I have several thousand
> lines total to plot.

Take a look at ?matplot or ?matlines depending upon which one might make
sense for your particular application. Both functions are on the same
help page.


Marc Schwartz

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