Re: [Plplot-general] Multiple charts in the same page

[Alan W. I. <Ala...@gm...>]

On 2021-11-14 15:00-0500 R Srinivasan wrote:

> Newbie here. Using PlPlot bindings of Ada.
>
> I am trying to create 2 plots to fit on the same page - as in the Real and
> Imaginary components of a complex signal.
>
> When I use the png output - only the first plot is ever seen. Same with jpg
> outputs. On the other hand, when pdf output is used 2 different pages are
> in the file and they contain the 2 plots.
>
> Example 2a appears to do something similar and the results are as outlined
> above.
>
> My platform is Windows with mingw64
>
> Clues appreciated. Thanks, Srini

Hi Srini:

First some background.

In general (i.e., this is an external requirement) some graphics
file types (e.g, PNG, JPEG) don't allow multiple pages while others
(e.g. PDF) do allow multiple pages.

PLplot works around that external issue for modern file device drivers
by providing an option to generate separate files for each multiple
page.  This concept is called familied files, and for more details
about that please look at
<http://plplot.org/docbook-manual/plplot-html-5.15.0/devices.html#familying>.

By the way, for the PNG format I would highly recommend using either
the pngcairo device or the pnqqt device.  If you build your own PLplot
those devices should be available for MSYS2 (which fully supports the
cairo and Qt libraries which those devices depend on).  On the other
hand, I would not recommend using the png device since that is
deprecated.

I think that backgrounds answers why you are getting different paging
results for different devices.  But to answer your specific question,
it appears you are trying to generate separate plots for a single page
(e.g., like <http://plplot.org/examples.php?demo=01>), and my guess is
you ran into the paging difficulties because of some mistake in your
code (e.g., forgetting to call plstar) that generated multiple pages
rather than just your desired single page with multiple plots.
Anyhow, if that is the case, please take a look at that example to see
what to do for the multiple plot per page case.

Cheers,

Alan
__________________________
Alan W. Irwin

Research affiliation with the Department of Physics and Astronomy,
University of Victoria, Victoria, BC, Canada.

Programming affiliations with the FreeEOS equation-of-state
implementation for stellar interiors (freeeos.sf.net); the Time
Ephemerides project (timeephem.sf.net); PLplot scientific plotting
software package (plplot.org); the libLASi project
(unifont.org/lasi); the Loads of Linux Links project (loll.sf.net);
and the Linux Brochure Project (lbproject.sf.net).
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Linux-powered Science
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