pylab without X11

[Willem-Jan Vriend]

I want to use pylab (matplotlib) on a machine without X11. I'm trying to
generate onthefly graphics for an apache2 web service, so they do not
have to be displayed on this machine !

When i do
pylab.figure()
I get the error
TclError: couldn't connect to display ":0.0"

I tried setting the DISPLAY environment variable to "", ":0.0" but I got
the same error message.

Any help is very much appreciated.

[marc]

Re: pylab without X11

This may help you ... or not

You may have to change your backend :

p13 of the matplotlib user guide: backends
p17 how to change the backend in the matplotlibrc

An example of matplotlibrc ( backend choice is at the beginning ):

http://matplotlib.sourceforge.net/matplotlibrc

You may choose PS or SVG or pdf, there might be other possibilities, I
do not know
To save the file : savefig



Marc




Willem-Jan Vriend a écrit :

I want to use pylab (matplotlib) on a machine without X11. I'm trying to
generate onthefly graphics for an apache2 web service, so they do not
have to be displayed on this machine !
>
When i do
pylab.figure()
I get the error
TclError: couldn't connect to display ":0.0"
>
I tried setting the DISPLAY environment variable to "", ":0.0" but I got
the same error message.
>
Any help is very much appreciated.

[marc]

Re: pylab without X11

This may help ... or not ( 2nd part )

try not to do pylab.figure()

in your script:
pylab.plot, or pylab.imshow or whatever you want to use
then
savefig("myFigu re.png") for example
do not use show()


in my case ( with the WXAgg backend ), it works, it generates the png file

Marc





Willem-Jan Vriend a écrit :

I want to use pylab (matplotlib) on a machine without X11. I'm trying to
generate onthefly graphics for an apache2 web service, so they do not
have to be displayed on this machine !
>
When i do
pylab.figure()
I get the error
TclError: couldn't connect to display ":0.0"
>
I tried setting the DISPLAY environment variable to "", ":0.0" but I got
the same error message.
>
Any help is very much appreciated.

[Willem-Jan Vriend]

Re: Re: pylab without X11

Thanks that worked ! I changed the backend to Agg.

Allthough a problem there is that with the backend Agg you only can
write the resulting image to a file or a file like object, it does not
accept the (apache) request handler to write the file to. And I do not
want to save the file to disk first before sending to the client.

WJV

marc wrote:

<div class="moz-text-flowed" style="font-family: -moz-fixed">This may
help you ... or not
>
You may have to change your backend :
>
p13 of the matplotlib user guide: backends
p17 how to change the backend in the matplotlibrc
>
An example of matplotlibrc ( backend choice is at the beginning ):

http://matplotlib.sourceforge.net/matplotlibrc

>
You may choose PS or SVG or pdf, there might be other possibilities, I
do not know
To save the file : savefig
>
>
>
Marc
>
>
>
>
Willem-Jan Vriend a écrit :

>I want to use pylab (matplotlib) on a machine without X11. I'm trying
>to generate onthefly graphics for an apache2 web service, so they do
>not have to be displayed on this machine !
>>
>When i do
> pylab.figure()
>I get the error
> TclError: couldn't connect to display ":0.0"
>>
>I tried setting the DISPLAY environment variable to "", ":0.0" but I
>got the same error message.
>>
>Any help is very much appreciated.

>
</div>
>