Re: [Gnuplot-info] Best way to plot lines with variable color?

[Jim K. <jek...@kl...>]

Jim Kleckner wrote:
 > What would be the recommended way to plot line segments with varying
 > color (a multicolored single line plot)?
 >
 > The 4.2 documentation says that "rgbcolor variable" "is only available
 > in 3D plotting mode (splot)".
 >
 > The 4.3 documentation doesn't mention this restriction.
 >
 > Can 4.3 take the color of line segments from a column of data?
 >
 > Is there any way to do this simply (or not) in 4.2.5?
 >
 > Thanks!


I got around to compiling the CVS/4.3 version of Gnuplot
and line segments do work with color.

However the demo script below works for png files but
gives the following error for pdf files:
  fatal exception: [2100] PDF_lineto: Function must not be called in 
'page' scope

Anyone run into this or suggest where to start?

I'm running:
   gnuplot from cvs sources as of today.
   PDF-Lib-Lite-7.0.4p4 (updated to freshest to test this)
   CYGWIN_NT-5.1 kleckner2 1.5.25(0.156/4/2) 2008-06-12 19:34 i686 Cygwin

Thanks!

PS, I'm still curious if someone knows of a way to plot 2D line segments
with color even in 4.2 gnuplot.



============= greenblackred.dem =============
#
# colorspec demo for line segments
#
# greenblackred.dat:
# 1	0	65280
# 2	1	0
# 3	0	16711680
# 4	1	0
# 5	0	65280
# 6	1	0
# 7	0	16711680
# 8	1	0
# 9	0	65280
#
set terminal png
set output "greenblackred.png"
reset
set xrange [ 0 : 10 ]
#plot 'greenblackred.dat' using 1:2 with lines                     title 
"simple sawtooth"
plot 'greenblackred.dat' using 1:2:3 with lines lc rgb variable   title 
"variable sawtooth"
set terminal pdf
set output "greenblackred.pdf"
plot 'greenblackred.dat' using 1:2 with lines                     title 
"simple sawtooth"
plot 'greenblackred.dat' using 1:2:3 with lines lc rgb variable   title 
"variable sawtooth"