Matplotlib 1.5.1 - Function pcolormesh throws Segmentation Fault

Dear colleagues,
I’ve done a build from source
of latest Matplotlib package and deployed it at our IBM z13 machine
(s390x). It uses the current release 1.5.1.
During the unit tests I found an issue
with a test case from NOAA which uses a pcolormesh draw function
with basemap.
Example 2: Plot data from an NWW3 GRiB2
file - [ here: http://polar.ncep.noaa.gov/waves/examples/usingpython.shtml]
The following line is causing a Segmentation
fault
error even when adding an 8GB swap memory to the process:

cs = m.pcolormesh(x,y,data,shading='flat',cmap=plt.cm.jet)

I also tryed to execute other, similar samples that use pcolormesh, but
receiving the same error. Is this a known issue or might it be be related

to the memory environment ? Any hints how
to debug this error?

Regards,
Claude Falbriard
Certified IT Specialist L2 - Middleware

···

**Phone:**55-13-99662-5703 | Mobile:55-13-98117-3316E-mail: claudef@…3779…

Could you try using faulthandler and post the traceback please? That’ll help us isolate the problem better.

Ben Root

···

On Wed, Feb 24, 2016 at 3:04 PM, Claude Falbriard <claudef@…3779…> wrote:

Dear colleagues,
I’ve done a build from source
of latest Matplotlib package and deployed it at our IBM z13 machine
(s390x). It uses the current release 1.5.1.
During the unit tests I found an issue
with a test case from NOAA which uses a pcolormesh draw function
with basemap.
Example 2: Plot data from an NWW3 GRiB2
file - [ here: http://polar.ncep.noaa.gov/waves/examples/usingpython.shtml]
The following line is causing a Segmentation
fault
error even when adding an 8GB swap memory to the process:

cs = m.pcolormesh(x,y,data,shading='flat',cmap=plt.cm.jet)

I also tryed to execute other, similar samples that use pcolormesh, but
receiving the same error. Is this a known issue or might it be be related

to the memory environment ? Any hints how
to debug this error?

Regards,
Claude Falbriard
Certified IT Specialist L2 - Middleware


**Phone:**55-13-99662-5703 | Mobile:55-13-98117-3316E-mail: claudef@…3779…


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Sorry, forgot to post the link: https://pypi.python.org/pypi/faulthandler/

···

On Wed, Feb 24, 2016 at 3:33 PM, Benjamin Root <ben.v.root@…287…> wrote:

Could you try using faulthandler and post the traceback please? That’ll help us isolate the problem better.

Ben Root

On Wed, Feb 24, 2016 at 3:04 PM, Claude Falbriard <claudef@…3779…> wrote:

Dear colleagues,
I’ve done a build from source
of latest Matplotlib package and deployed it at our IBM z13 machine
(s390x). It uses the current release 1.5.1.
During the unit tests I found an issue
with a test case from NOAA which uses a pcolormesh draw function
with basemap.
Example 2: Plot data from an NWW3 GRiB2
file - [ here: http://polar.ncep.noaa.gov/waves/examples/usingpython.shtml]
The following line is causing a Segmentation
fault
error even when adding an 8GB swap memory to the process:

cs = m.pcolormesh(x,y,data,shading='flat',cmap=plt.cm.jet)

I also tryed to execute other, similar samples that use pcolormesh, but
receiving the same error. Is this a known issue or might it be be related

to the memory environment ? Any hints how
to debug this error?

Regards,
Claude Falbriard
Certified IT Specialist L2 - Middleware


**Phone:**55-13-99662-5703 | Mobile:55-13-98117-3316E-mail: claudef@…3779…


Site24x7 APM Insight: Get Deep Visibility into Application Performance

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Matplotlib-users mailing list

Matplotlib-users@lists.sourceforge.net

https://lists.sourceforge.net/lists/listinfo/matplotlib-users

Dear colleagues,

Thanks for the quick feedback.

I’ve installed the “faulthandler”
package, added it to the import and enabled it with faulthandler.enable().

Below the console trace of the test
using the pcolormesh function and the traceback information:

python test3.py

Fatal Python error: Segmentation fault

Current thread 0x000003ffa45f7710 (most recent call first):
File "/usr/lib64/python2.7/site-packages/matplotlib/collections.py", line 1877 in draw
File "/usr/lib64/python2.7/site-packages/matplotlib/artist.py", line 61 in draw_wrapper
File "/usr/lib64/python2.7/site-packages/matplotlib/axes/_base.py", line 2324 in draw
File "/usr/lib64/python2.7/site-packages/matplotlib/artist.py", line 61 in draw_wrapper
File "/usr/lib64/python2.7/site-packages/matplotlib/figure.py", line 1159 in draw
File "/usr/lib64/python2.7/site-packages/matplotlib/artist.py", line 61 in draw_wrapper
File "/usr/lib64/python2.7/site-packages/matplotlib/backends/backend_agg.py", line 474 in draw
File "/usr/lib64/python2.7/site-packages/matplotlib/backends/backend_agg.py", line 527 in print_png
File "/usr/lib64/python2.7/site-packages/matplotlib/backend_bases.py", line 2232 in print_figure
File "/usr/lib64/python2.7/site-packages/matplotlib/figure.py", line 1565 in savefig
File "/usr/lib64/python2.7/site-packages/matplotlib/pyplot.py", line 688 in savefig
File "test3.py", line 47 in <module>
Segmentation fault

Hope this information helps to circle the
issue.

Regards,
Claude Falbriard
Certified IT Specialist L2 - Middleware

···

**Phone:**55-13-99662-5703 | Mobile:55-13-98117-3316E-mail: claudef@…4510…9…

From:
Benjamin Root <ben.v.root@…287…>
To:
Claude Falbriard/Brazil/IBM@…4709…
Cc:
Matplotlib Users matplotlib-users@lists.sourceforge.net
Date:
24/02/2016 17:35
Subject:
Re: [Matplotlib-users]
Matplotlib 1.5.1 - Function pcolormesh throws Segmentation Fault


Sorry, forgot to post the link: https://pypi.python.org/pypi/faulthandler/
On Wed, Feb 24, 2016 at 3:33 PM, Benjamin Root <ben.v.root@…287…> wrote:
Could you try using faulthandler and post the traceback
please? That’ll help us isolate the problem better.
Ben Root
On Wed, Feb 24, 2016 at 3:04 PM, Claude Falbriard <claudef@…3779…> wrote:
Dear colleagues,
I’ve done a build from source of latest Matplotlib package
and deployed it at our IBM z13 machine (s390x). It uses the current release
1.5.1.
During the unit tests I found an issue with a test case from NOAA which
uses a pcolormesh draw function with basemap.
Example 2: Plot data from an NWW3 GRiB2 file - [ here: http://polar.ncep.noaa.gov/waves/examples/usingpython.shtml]
The following line is causing a Segmentation fault error even when
adding an 8GB swap memory to the process:
cs = m.pcolormesh(x,y,data,shading='flat',cmap=plt.cm.jet)

I also tryed to execute other, similar samples that use pcolormesh, but
receiving the same error. Is this a known issue or might it be be related

to the memory environment ? Any hints how to debug this error?
Regards,
Claude Falbriard
Certified IT Specialist L2 - Middleware


**Phone:**55-13-99662-5703| Mobile:55-13-98117-3316E-mail: claudef@…3779…


Site24x7 APM Insight: Get Deep Visibility into Application Performance
APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month
Monitor end-to-end web transactions and take corrective actions now
Troubleshoot faster and improve end-user experience. Signup Now!
http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140


Matplotlib-users mailing list
Matplotlib-users@…1220…sts.sourceforge.net
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