Re: [Gnuplot-info] Data File with Group-Indexed Lines

[walter h. <wh...@bf...>]

Am 28.09.2012 16:02, schrieb Yub Yub:
> Hi all, I'm new to gnuplot.
> 
> I'm using gnuplot 4.6.0 on Ubuntu 12.04.
> 
> 
> I've done a bunch of reading of tutorials and documentation, though there are some things I'm having trouble figuring out how to do (or even if it's possible to do).
> 
> In particular at the moment, I have the following issue -- which has been hard to search for solutions to, since the associated keywords are common to other questions and issues.
> 
> I have a file with columns of data which I would like to plot -- which is simple enough.
> However, one of the columns is an index, which denotes which data-set the line belongs to.
> (The lines are all in one long mixed group -- there are no sections or extra newlines.)
> 
> I would like to create a separate graph for each index in the file.
> 
> I found in the documentation[1] how to use the ternary operator to omit values based on column values, but this approach has several problems.
> 
> First, the documentation recommends setting points to undefined (1/0), which means that if I'm plotting "with linespoints", then any time there are consecutive lines in the file which have different indices, there is a break in the graph.
> 
> Second, it seems that I would need to know all of the indices in the file before running gnuplot on it, so that I could tell it to plot each of the different indices. (Using a loop perhaps, but I'd still need to know them all beforehand.)
> 
> One solution is to simply write a simple (eg. Python) script to parse the data file beforehand to sort/reformat it, break it into multiple files or sections, or something like that. Then it could create gnuplot code to hand it off to.
> 
> However, I would like to know if I can accomplish this using only gnuplot, for an arbitrary file.
> 
> Thank you so much!
> -Yub
> 
> 

so far i understand you have a file with a index,value pair like that:

0       73      0       25      0       124302  000000.003107550
0       74      0       28      0       150160  000000.003754000
0       75      0       39      0       244268  000000.006106700
0       76      1       87      0       259467  000000.006486675
0       77      0       149     0       259537  000000.006488425
0       78      0       32      0       268263  000000.006706575
0       79      1       282     0       281296  000000.007032400
0       80      0       481     0       281366  000000.007034150
0       81      0       13      1       36992   000000.010924800
0       82      1       134     1       56228   000000.011405700
0       83      0       228     1       56298   000000.011407450
0       84      1       100     1       77730   000000.011943250
0       85      0       171     1       77800   000000.011945000
0       86      0       115     1       77981   000000.011949525
0       87      1       34      1       275359  000000.016883975

lets assume that column 3 is your index and column 7 is you value.
I am not sure if gnuplot is intended to do such filtering. So i use
awk for that, i found it very flexible an easy to use and less fat
than certain other languages.

awk '{ print $7 >>$3 }' [your file here]

This would generate a file called 1 and a second called 0 feel free to ajust to you needs.
You can run that script from inside gnuplot also by using

plot "<awk '{ if ($3==0) print $7 }' " but this would require a recalculation everytime
you want a plot.


re,
 wh