help in capturing matrix patterns to files

[abdul-rahman at tu-harburg.de]

Many thanks everyone for the inputs/alternatives.

On Thu, 4 May 2006, Barry Smith wrote:

>
>    You can simply use -mat_view_draw -draw_type ps and it will save the
> image in defaultps0.ps
>
>    Draw backs:
> 1) only generates color postscript
>
> 2) silly file name defaultps0.ps
>
> 3) the file can get large, megabytes for moderately large matrices (cause it
> draws EVERY non-zero matrix element).
>
>    I have added to
> http://www-unix.mcs.anl.gov/petsc/petsc-as/developers/projects.html
> 1) -draw_ps_monochrome (and corresponding function) to get black and white ps
>
> 2) -draw_ps_filename for allowing changing the name of the file.

Will try this out one of these days.

> The image looks fine, but I do think that Matlab's spy() function
> does generate a more visually appealing image. Heck they have graphics
> experts while I learned my limited postscript by reverse engineering
> postscript files in the early 90's :-(

For what it's worth, I tried to push how big a matrix matlab can take. My
ascii file in Matlab format is 130M in size, with n~17k, nnz~2.2M
(complex). Matlab simply could not read it. :). Well, i guess it could,
but I didn't want to wait for a couple hours just to "spy" a matrix.

I think for now the X tool suffices me. I never knew it exists. Thanks for
pointing out.

Many thanks again!


Razi