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Iterating over powers of two in gnuplot

I want to plot data stored in a bunch of files using gnuplot. If the files were named using sequential numbers (eg "1.dat" "2.dat", ...) I would use something like

plot for [i=1:10] i.'.dat' u 1:2 w lp t 'I='.i;

However, now the files are named using authority 2, ie "2.dat", "4.dat", "8.dat", .... I tried

plot for [i=1:10] (2**i).'.dat' u 1:2 w lp t 'I='.(2**i);

but i am getting error

STRING operator applied to non-STRING type

I'm guessing this is happening because gnuplot counts (2**i)

as floating point, not integer.

I am sure there is a way to do what I want to do, but since I am very new to using gnuplot control statements, I cannot figure out how to do this. Can someone please help me?

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2 answers


You can use sprintf

to convert number to string:

plot for [i=1:10] sprintf('%d',2**i).'.dat' u 1:2 w lp t 'I='.(2**i)


Interestingly, the concatenation (2**i)

with 'I='

in the header doesn't cause problems.

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Try using an empty string ( ""

) to start your string concatenation operation. This is "".(2**i).".dat"

instead (2**i).".dat"

.



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