Dirty hacks
Points with different colors
ctioga is not yet able to handle 3-dimensional sets. But, sometimes,
you can emulate a 3D behavior. Here is an example: I was requested to
come up with a way to color points of a graph according to a certain
column.
The first step to achieve this is to be able to color all points
differently. For that, I use a trick based on the 1##10 dataset
expansion and some ruby code to turn a single data file into a hundred
different sets (as much as there are points), and I use the
gradient colorset to color each one differently.
ctioga --xpdf --marker Circle -N \
--line-style no --marker-scale 0.3 \
--color-set gradient:Red--Green,100 \
trig.dat@'$1:if $0 == 0##99; $2; else nan; end'
Then, once this is made, it is easy to select the color according to a different column. There is a version where the color is chosen based on the value of column 3:
ctioga --xpdf -N trig.dat@1:3 --marker Circle \
--line-style no --marker-scale 0.3 \
--color-set gradient:Red--Green,11 \
trig.dat@'$1:;a = 0##9 * 0.2 - 1; b = $3; if((b>= a) && (b <= a+0.2)); $2; else nan; end'
Please note the ; at the beginning: it prevents ctioga from
interpreting a = as a thing of the like of yerr= (for
errorbars). Please note that, as of version 1.6, you need to make sure
that no set is empty in the end (all sets produced have at least one
element). If you fail to do so, ctioga will crash (but I’ll correct
that for a later version).
