[Scilab-users] Headless graphics in scilab: time & memory issues

Hello all,

In other words, I connect  in command line only to a remote server where scilab is installed and I want it to generate graphics using a combination of driver, xinit and xend.

For example, a simple Sgrayplot that takes ~1 second to plot and save to a png in normal mode takes more than 200 seconds and huge amount of ram in headless mode (see attached test script).

I also have some plots that works without a problem in normal mode, but fail in headless mode because of some memory limitation:

xend: An error occurred: Unable to create export file, not enough memory. Decreasing the number of elements or the size of the figure should fix this error.

Is there a way to get around these problems?

Thanks for your help,

Antoine

xend_test.sce (666 bytes) Download Attachment

Hello again,

Just to add to my previous message: increasing nx or ny in my script can crash scilab during the call to xend().
On my small local machine, this occurs for:

nx=4000;
ny=3000;

for which scilab takes ~7 seconds to create the png in "normal" mode...

Can any of you confirm this bug?

Antoine

Hello all,

In these days of remote working, I need to use again scilab in headless mode to generate graphics.

In other words, I connect  in command line only to a remote server where scilab is installed and I want it to generate graphics using a combination of driver, xinit and xend.

There seems to be some issues with driver/xinit/xend: huge memory overhead and long computation time that makes it impossible to generate some plots in headless mode.

For example, a simple Sgrayplot that takes ~1 second to plot and save to a png in normal mode takes more than 200 seconds and huge amount of ram in headless mode (see attached test script).

I also have some plots that works without a problem in normal mode, but fail in headless mode because of some memory limitation:

xend: An error occurred: Unable to create export file, not enough memory. Decreasing the number of elements or the size of the figure should fix this error.

Is there a way to get around these problems?

Thanks for your help,

Antoine

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Hello Antoine,

Exporting in headless mode (all drivers but the default "Rec") is fundamentally different from the default "Rec" mode where graphics are actually rendered on screen on a joGL Canvas. In this case there is virtually no overhead when exporting this Canvas to a bitmap image format (png,jpeg,gif,...). In headless mode the rendering cannot use joGL and there is the same overhead as when you try to export a figure to a vectorial format (svg,pdf,eps) :

nx=4000;
ny=300;
nc=100;

x=1:nx;
y=[1:ny].';
z=(y*x);

driver Rec
h=scf();
h.color_map=hotcolormap(nc);
Sgrayplot(x,y,z.');
xs2pdf(h,"screen.pdf")

at line    13 of executed file /Users/mottelet/Desktop/xend_test.sce

xs2pdf: Unable to create export file, not enough memory. Decreasing the number of elements or the size of the figure should fix this error.

S.

Hello all,

In these days of remote working, I need to use again scilab in headless mode to generate graphics.

In other words, I connect  in command line only to a remote server where scilab is installed and I want it to generate graphics using a combination of driver, xinit and xend.

There seems to be some issues with driver/xinit/xend: huge memory overhead and long computation time that makes it impossible to generate some plots in headless mode.

For example, a simple Sgrayplot that takes ~1 second to plot and save to a png in normal mode takes more than 200 seconds and huge amount of ram in headless mode (see attached test script).

I also have some plots that works without a problem in normal mode, but fail in headless mode because of some memory limitation:

xend: An error occurred: Unable to create export file, not enough memory. Decreasing the number of elements or the size of the figure should fix this error.

Is there a way to get around these problems?

Thanks for your help,

Antoine

_______________________________________________
users mailing list
[hidden email]
https://antispam.utc.fr/proxy/1/c3RlcGhhbmUubW90dGVsZXRAdXRjLmZy/lists.scilab.org/mailman/listinfo/users

-- 
Stéphane Mottelet
Ingénieur de recherche
EA 4297 Transformations Intégrées de la Matière Renouvelable
Département Génie des Procédés Industriels
Sorbonne Universités - Université de Technologie de Compiègne
CS 60319, 60203 Compiègne cedex
Tel : +33(0)344234688
http://www.utc.fr/~mottelet

Hello again,

Just to add to my previous message: increasing nx or ny in my script can crash scilab during the call to xend().
On my small local machine, this occurs for:

nx=4000;
ny=3000;

for which scilab takes ~7 seconds to create the png in "normal" mode...

Can any of you confirm this bug?

The crash is due to a too small Java Heap of memory.
When increasing it through the user's Preferences from 256 MB to 1 GB, the PNG export works as fast as expected.
I get i nice png image from 4000x3000 with
--> tic(); Sgrayplot(x,y,z.'); toc()
 ans  =
   8.1342045

--> tic(); xs2png(0, "test.png"); toc
 ans  =
   0.4060765

figure("visible","off")  allows to avoid using driver(), but the same memory consumption is then observable, when exporting the Sgrayploy with xs2png().

nx=4000;
ny=300;
nc=100;

x=1:nx;
y=[1:ny].';
z=(y*x);

h = figure("visible","off");
h.color_map=hotcolormap(nc);
Sgrayplot(x,y,z.');
xs2png(h,"C:/windows/temp/figure.png")

Hello all,

In these days of remote working, I need to use again scilab in headless mode to generate graphics.

In other words, I connect  in command line only to a remote server where scilab is installed and I want it to generate graphics using a combination of driver, xinit and xend.

There seems to be some issues with driver/xinit/xend: huge memory overhead and long computation time that makes it impossible to generate some plots in headless mode.

For example, a simple Sgrayplot that takes ~1 second to plot and save to a png in normal mode takes more than 200 seconds and huge amount of ram in headless mode (see attached test script).

I also have some plots that works without a problem in normal mode, but fail in headless mode because of some memory limitation:

xend: An error occurred: Unable to create export file, not enough memory. Decreasing the number of elements or the size of the figure should fix this error.

Is there a way to get around these problems?

Thanks for your help,

Antoine

_______________________________________________
users mailing list
[hidden email]
http://lists.scilab.org/mailman/listinfo/users