Plotting multiple data series with multiple styles in a gnuplot for loop

1
votes

I'm trying to generate some plots with gnuplot, with both lines and error bars, but I'm running into some trouble. When I run this code (with no prior definition of i, but a prior definition of m = 9):

plot for [i=2:5] \
'../Data/Clustering/c_vs_n_with_error_'.i.'ball_m'.m.'.txt' u 1:2 w linespoints t ''.i.'-Ball', \
'../Data/Clustering/c_vs_n_with_error_'.i.'ball_m'.m.'.txt' u 1:2:3 w yerrorbars t ''

I get the following error:

warning: Skipping unreadable file "../Data/Clustering/c_vs_n_with_error_6ball_m9.txt"

And there is, in fact, no file of that name. My issue is that the resulting plot does not have error bars (it's plotted in the lines-only style); it's as if the second use of the same file is simply ignored. However, when I change the iteration range to [i=2:4], I receive no error - and the data range for the i=5 is plotted with error bars instead of lines.

I am plotting this way because other information I explored told me that it was not possible to plot with multiple styles (linespoints and yerrorbars) simultaneously, and that this was a good solution (but it gave examples only for a single data series, without a for loop).

Two things I would like to avoid doing are a) writing out all the files (without using iteration) and b) resorting to a shell script, because I'd much rather prefer to understand gnuplot than work around it.

Thank you for your help!

1
for-loopgnuplot

1 Answers

2
votes

The scope of an iteration ends at the next comma or the end of the command, whichever comes first. Compare e.g the following two examples (from the gnuplot manual):

plot for [i=1:3] j=i, sin(j*x)

and

plot for [i=1:3] j=i sin(j*x)

Accordingly, you can change your plot command to:

file(n) = sprintf('../Data/Clustering/c_vs_n_with_error_%dball_m'.m.'.txt', n)
plot for [i=2:5] file(i) u 1:2 w linespoints t ''.i.'-Ball', \
     for [i=2:5] file(i) u 1:2:3 w yerrorbars t ''