My question is very simple. Suppose I have a datafile with column headers, like as follows
first second
1 1
2 1
3 6
4 9
In gnuplot how do i make it so that the datafile is plotted using the column header as axis label? e.g. by calling
plot datafile using 1:2
i get the xaxis labeled first and the yaxis labeled second?
edit: I do know that I can use the column header as a key entry via set key auto title column head, however that's not quite what I'm looking for.
To elaborate the suggestion of @andyras, here is how you can do it:
datafile = 'filename.txt'
firstrow = system('head -1 '.datafile)
set xlabel word(firstrow, 1)
set ylabel word(firstrow, 2)
plot datafile using 1:2
You must plot with the explicit using statement, otherwise gnuplot will complain about bad data on line 1.
Another question where people believe it can't be done with gnuplot. Here is a simple gnuplot-only solution without external tools, hence platform-independent.
Data: SO16089301.dat
first second
1 1
2 1
3 6
4 9
Script: (works with gnuplot 4.6.0, March 2012)
### extracting axes labels from datafile
reset
FILE = 'SO16089301.dat'
stats FILE u (myX=strcol(1), myY=strcol(2)) every ::0::0 nooutput
set xlabel myX
set ylabel myY
plot FILE u 1:2 w lp pt 7 lc rgb "red"
### end of script
Result:
I don't think this feature is built in to gnuplot; you would probably have to use an awk-like utility to pull those labels out of a datafile.
You could try submitting a feature request on gnuplot's sourceforge site, and get feedback from the developers there.
awk + head -1 should do it.I think it is supported. You are just supposed to be able to use "":
plot 'file' using "first":"second"
Although, if you want to do math in your using specification, you'll need the column("") function, too
plot 'file' using "first":(column("second")-(column("thrid"))
(Using only quoted header names with the math didn't work for me, anyway.)
