Someone wrote to me and asked if I found a solution to a problem that
I described in a posting to Statalist in March. Yes, I did and I
apologize for not having shared the solution with the list sooner.
I was looking for a way to specify the size of PNG graphs that are
exported from Stata. Stata tech support suggested that this can be
done by exporting the graph as a PostScript file and converting it to
PNG format with a third-party utility like Ghostscript
(www.ghostscript.com). Ghostscript can be called from a do-file via a
shell command to automate the creation of PNG files. The example
below creates a PNG file with the dimensions 500 by 400 pixels.
#delimit ;
sysuse auto;
* Set options for PostScript export;
graph set ps pagesize custom;
graph set ps pagewidth 5;
graph set ps pageheight 4;
graph set ps tmargin 0;
graph set ps lmargin 0;
graph set ps logo off;
graph set ps fontface Helvetica;
* Draw graph and export to PostScript file;
scatter mpg weight, xsize(5) ysize(4);
graph export "scatter.ps";
* Convert PostScript file to PNG format;
shell "C:\gs\gs8.51\bin\gswin32c.exe"
-dSAFER -dBATCH -dNOPAUSE
-r100 -g500x400 -sDEVICE=png16m
-dGraphicsAlphaBits=4 -dTextAlphaBits=4
-sOutputFile="scatter.png" "scatter.ps";
A detailed explanation of the process an be found at these sites
(both contain the same text):
http://huebler.info/2005/20050407_Stata_PNG.html
http://huebler.blogspot.com/2005/04/creating-png-images-with-stata.html
I work with Stata 8.2 and don't know if this is still an issue with
Stata 9.
Friedrich Huebler
--- Friedrich Huebler <[email protected]> wrote:
> I would like to export graphs to PNG format with a specific size,
> for example 500 by 375 pixels. Apparently the only way to get this
> size is through trial and error by repeatedly resizing the graph
> window, exporting the graph, and checking its size in an image
> viewer.
>
> The xsize(#) and ysize(#) options don't have an effect, at least
> when the ratio x/y doesn't change. David Harrison mentioned this in
> a post to Statalist last month
> (http://www.stata.com/statalist/archive/2005-02/msg00309.html). You
> can try this yourself:
>
> . sysuse auto
> . scatter mpg weight, xsize(5) ysize(4)
> . scatter mpg weight, xsize(2.5) ysize(2)
> . scatter mpg weight, xsize(2.5) ysize(1)
> . scatter mpg weight, xsize(5) ysize(2)
>
> The first two -scatter- commands draw graphs of exactly the same
> size, as do the last two -scatter- commands. The graph changes from
> the second to the third -scatter- command because the ratio x/y is
> different.
>
> Has anyone found a way to create PNG graphs of a specific size that
> doesn't require manual resizing of the graph window? Does Statacorp
> plan to add an option to specify graph size in pixels?
>
> Thank you,
>
> Friedrich Huebler
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