Re: [Gnuplot-info] string variables and iteration (gnuplot 4.6)

[Leo B. <l_b...@us...>]

>   Date: Thu, 19 Sep 2013 04:51:31 -0700
>   From: "atoms.h" <tho...@gm...>
>   Content-Type: text/plain; charset="us-ascii"
>
>   Hi,
>
>   I'm trying to make use of the iteration feature, so far unsuccessfully. I
>   want to plot files in different directories with the same file name. All in
>   one pdf documents. The way I construct my paths is by means of string
>   variables:
>
>   $ basefolder = '../data/scalePr/'
>   $ folder1 = '0.90'
>   $ folder2 = '0.95'
>   $ folder3 = '0.97'
>   $ folder4 = '1.00'
>   $ file1 = basefolder.folder1."/".filename.".dat"
>   $ file2 = basefolder.folder2."/".filename.".dat"
>   $ file3 = basefolder.folder3."/".filename.".dat"
>   $ file4 = basefolder.folder4."/".filename.".dat"
>
>   I haven't figured out a way to iterate through variable names like
>
>   $ file(n) = basefolder.folder.sprintf("%d",n)."/".filename.".dat"
>
>   (which obviously doesn't work) to be able to do multiple plots in one
>   command:
>
>   $ do for [i=1:4]{
>   $     splot file(i)
>   $ }
>
>   If anyone has an idea how to iterate variable names it would be most
>   appreciated!

It is probably best to use strings with separators to implement a type
of read-only string array. Here is one such effort

gnuplot> directory="/home/user"
gnuplot> files="a0 a1 a2 a3 "
gnuplot> sep=" "
gnuplot> c=strstrt(files,sep);
gnuplot>
gnuplot> while (c) { w=sprintf("%s/%s",directory,files[0:c-1]);
more> print w;
more> files=files[c+1:*]
more> c=strstrt(files,sep);
more> }
/home/user/a0
/home/user/a1
/home/user/a2
/home/user/a3

With a bit more work you can make a custom iterator:

gnuplot> files="a0 a1 a2 a3 a4 a5 a6 "
gnuplot> iterate_over_(string,sep,cmd,s,c)=(c == 0 ? s :\
>iterate_over_(string[c+1:*],sep,cmd,s . (c == -1 ? "" : sprintf(cmd,string[0:with_iterate_over_c-1])), strstrt(string[c+1:*],sep)));
gnuplot> iterate_over(string,sep,cmd)=iterate_over_(string,sep,cmd,"",-1);
gnuplot>
gnuplot> print iterate_over(files,sep,"file='%s'; splot directory .'/'. file;\n")
file='a0'; splot directory .'/'. file;
file='a1'; splot directory .'/'. file;
file='a2'; splot directory .'/'. file;
file='a3'; splot directory .'/'. file;
file='a4'; splot directory .'/'. file;
file='a5'; splot directory .'/'. file;
file='a6'; splot directory .'/'. file;

Leo