I'm trying to plot a histogram in gnuplot, where the bars are characterized by their color (intensity) instead of their height (frequency). To do so, I want to fill each bar with a color corresponding to the third column (which stands for this intensity) of a data file, defined in a palette. All the bars have the same height y=1 and the same width dx=1. The important part of the script looks like
plot for [ii=0:N] 'data.dat' index ii u 1:2:3 w filledcu y1=0 lc palette
My problem is that the ii=0 takes the right color of the palette and fills the first bar, but from there on all the others are the same color ( same intensity ) than ii=0.
My data file looks like:
X Y Intensity
1 1 0.6
2 1 0.6
...
Any idea to fill with the right color ?
The filledcurves plotting style doesn't support color gradients, see Gnuplot filledcurves with palette.
Since you have the same height for every bar, you can use the boxes plotting style:
set style fill solid noborder
plot 'data.dat' using 1:2:3 with boxes lc palette