gnuplot-beta

files for plotting given by string function

[Petr M. <mi...@ph...>]

I tried to generate filename via a string function, and plot them (sometimes
filenames are very long). For example:

f(n)='a'.n.'.dat'
plot f(1), f(2)

=> it should be equivalent to plot 'a1.dat', 'a2.dat'. However, gnuplot
complains:

	warning: encountered a string when expecting a number
	NB: you cannot plot a string-valued function

I wish it behaves like I expect, i.e. string means filename.

Ethan, could you change this behaviour?

---
PM

Re: files for plotting given by string function

[Lutz M. <ma...@uc...>]

On Wednesday 15 June 2005 05:51, Petr Mikulik wrote:
> f(n)='a'.n.'.dat'
> plot f(1), f(2)
>
> => it should be equivalent to plot 'a1.dat', 'a2.dat'. However, gnuplot

I was wondering if it would be feasible to include shell-like wildcard 
expansion into gnuplot. For example, if there a two files a.1.dat and a.2.dat 
in the current working directory,
  plot "a.*.dat"
should be interpreted as
  plot "a.1.dat", "a.2.dat"

Is it possible to do this in a platform-independent way? I currently use the 
little script "pl" (http://www.phys.uni-paderborn.de/~stern/pl/) to use the 
globbing features of the shell, but there are quite a few things that would 
be much easier to do in an interactive gnuplot session.

  Lutz

Re: files for plotting given by string function

[Ethan M. <merritt@u.washington.edu>]

On Wednesday 15 June 2005 09:43 am, Lutz Maibaum wrote:
> 
> I was wondering if it would be feasible to include shell-like wildcard 
> expansion into gnuplot. For example
>   plot "a.*.dat"
> 
> Is it possible to do this in a platform-independent way? I currently use the 
> little script "pl" (http://www.phys.uni-paderborn.de/~stern/pl/) to use the 
> globbing features of the shell, but there are quite a few things that would 
> be much easier to do in an interactive gnuplot session.

With the bleeding-edge cvs patch from Juergen Wieferink to implement a
system() call, you could use a similar perlscript to do something along
the lines of:

  set macros
  file_list = system("ls -1 a.*.dat | dirlist.pl")
  plot @file_list


where dirlist.pl is a cleaned up version of this quick perl hack
(which leaves a missing " at the start of the line and an extra ," at the end,
but you get the idea)

#!/usr/bin/perl -w
  while (<>) {
	s/\n/", "/;
	print;
  }


In fact, if you use the equally bleeding-edge substring manipulation code
you can do the cleanup inside gnuplot. The following actually works
when run in the source directory using yesterday's cvs version with
Juergen's patch:

  set macros
  file_list = system("ls -1 ../demo/?.dat | ./dirlist.pl")
  file_list = "\"".file_list
  file_list = file_list[0:strlen(file_list)-4]

  plot @file_list


-- 
Ethan A Merritt       merritt@u.washington.edu
Biomolecular Structure Center
Mailstop 357742
University of Washington, Seattle, WA 98195

Re: files for plotting given by string function

[<wie...@we...>]

On Wednesdy, 15 June 2005 23:36, Ethan Merritt wrote:
> With the bleeding-edge cvs patch from Juergen Wieferink to implement a
> system() call, you could use a similar perlscript to do something along
> the lines of:
>
>   set macros
>   file_list = system("ls -1 a.*.dat | dirlist.pl")
>   plot @file_list

In this special case, backtic substition will already do the job:

  plot `ls -1 a.*.dat | dirlist.pl`

But feel free to try the patch and report bugs or suggest
enhancements. :-)


Juergen

Re: files for plotting given by string function

[Lutz M. <ma...@uc...>]

On Thursday 16 June 2005 00:23, J=FCrgen Wieferink wrote:
> On Wednesdy, 15 June 2005 23:36, Ethan Merritt wrote:
> >   set macros
> >   file_list =3D system("ls -1 a.*.dat | dirlist.pl")
> >   plot @file_list
>
> In this special case, backtic substition will already do the job:
>
>   plot `ls -1 a.*.dat | dirlist.pl`

The problem with this is that it produces a plot with only a single item,=20
i.e., all the different files have the same (point|line)style. I was hoping=
=20
for a shortcut to automatically plot many files, each with a different styl=
e.

  Lutz

Re: files for plotting given by string function

[Ethan M. <merritt@u.washington.edu>]

On Friday 17 June 2005 12:48 pm, Lutz Maibaum wrote:
> On Thursday 16 June 2005 00:23, J=FCrgen Wieferink wrote:
> > On Wednesdy, 15 June 2005 23:36, Ethan Merritt wrote:
> > >   set macros
> > >   file_list =3D system("ls -1 a.*.dat | dirlist.pl")
> > >   plot @file_list
> >
> > In this special case, backtic substition will already do the job:
> >
> >   plot `ls -1 a.*.dat | dirlist.pl`
>=20
> The problem with this is that it produces a plot with only a single item,=
=20
> i.e., all the different files have the same (point|line)style. I was hopi=
ng=20
> for a shortcut to automatically plot many files, each with a different st=
yle.

Huh?  No it doesn't.  It expands to
      plot "a.1.dat", "a.2.dat", "a.3.dat", ...

So each plot gets a new line/point style.
I know it works, because I actually tested it using the short script
in my previous Email. An even simpler demo of the principle is

gnuplot> plot `demo.pl`

where=20

#~/usr/bin/perl
# demo.pl
  print " '1.dat', '2.dat', '3.dat' "




=2D-=20
Ethan A Merritt       merritt@u.washington.edu
Biomolecular Structure Center
Mailstop 357742
University of Washington, Seattle, WA 98195

Re: files for plotting given by string function

[Lutz M. <ma...@uc...>]

On Friday 17 June 2005 13:14, Ethan Merritt wrote:
> On Friday 17 June 2005 12:48 pm, Lutz Maibaum wrote:
> > The problem with this is that it produces a plot with only a single item,
> > i.e., all the different files have the same (point|line)style. I was
> > hoping for a shortcut to automatically plot many files, each with a
> > different style.
>
> Huh?  No it doesn't.  It expands to
>       plot "a.1.dat", "a.2.dat", "a.3.dat", ...

My apologies, I wrote my email before actually trying it out. My bad. This 
might afterall be exactly what I'm looking for.

  Lutz

Re: files for plotting given by string function

[Juergen W. <wie...@fr...>]

Am Freitag, 17. Juni 2005 21:48 schrieb Lutz Maibaum:
> On Thursday 16 June 2005 00:23, J=FCrgen Wieferink wrote:
> > In this special case, backtic substition will already do the job:
> >
> >   plot `ls -1 a.*.dat | dirlist.pl`
>
> The problem with this is that it produces a plot with only a single item,
> i.e., all the different files have the same (point|line)style. I was hopi=
ng
> for a shortcut to automatically plot many files, each with a different
> style.

Have you actually tried?  I get each file with its own line- and
pointstyle.

It may be possible to get the "dirlist.pl" simpler than the
following, though...

  #!/usr/bin/perl -w
  my $save =3D "\"";
  while (<>) {
      print $save;
      s/\n/", "/;
      $save =3D $_;
  }
  $save =3D~ s/, \"$//;
  print $save;


Juergen