Runtime Error - Need Advice

Use pylab.savefig('log_plot'). Also saving the figure to file and
showing it interactively in the same script might involve switching
backends, which might not work as expected.

It is advisable to downgrade to numpy 1.3.

-- Christoph


On 2/9/2010 10:44 AM, Lee Boger wrote:

Although, if I close the figure then re-run the script, a new figure
pops up but it doesn't have any data plotted. Interpreter is now locked
up. I'm still not fixing it completely. There is also no figure stored
as a file log_plot.


*Christoph Gohlke <cgohlke@...2143...>*

02/09/2010 01:23 PM

  Lee Boger <Boger_Lee@...2968...>
  Re: [Matplotlib-users] Runtime Error - Need Advice

Caterpillar: Confidential Green Retain Until: 03/11/2010

Change the last line to and it should work.

Anyway, this example should not crash the interpreter. I can reproduce
the crash on Python 2.4, 2.5, and 2.6 (32 and 64 bit) on Windows with
mpl 0.99.1 but not on Ubuntu 9.1 with mpl 0.99.0.

The shortest example that crashes is:

python -c "import pylab;pylab.subplot(111)"

or on the interactive prompt:

import pylab

Fatal Python error: PyEval_RestoreThread: NULL tstate

This application has requested the Runtime to terminate it in an unusual
Please contact the application's support team for more information.

-- Christoph

On 2/9/2010 7:57 AM, Lee Boger wrote:

Windows XP Professional with Python 2.5 installed (pywin32 build 210) -
came with dSPACE software package

Downloaded and installed matplotlib-0.99.1.win32-py2.5.exe from

Downloaded and installed numpy-1.4.0-win32-superpack-python2.5.exe from

Executing the following simple "log plot" script within PythonWin:

*from* matplotlib *import* pylab

# Create some artificial data.
test_frequency = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
17, 18, 19, 20]
test_results = [-0.2, -0.7, -1.0, -1.5, -2.0, -2.5, -3.0, -3.5, -4, -5,
-6, -7.1, -8, -9, -10, -11, -12, -15, -20, -25]
spec_frequency = [6, 8]
spec_results = [-3.0, -3.0]

# Plot
figure = pylab.subplot(111)
figure.scatter(test_frequency, test_results, s=20, c='b', marker='s',
figure.scatter(spec_frequency, spec_results, s=40, c='g', marker='s',
figure.set_xlabel(r"Frequency (Hz)", fontsize = 12)
figure.set_ylabel(r"Actuator Response (db)", fontsize = 12)


Plots a figure on the screen that looks correct, then the following
error (when I click OK, PythonWin closes)

Any advice would be appreciated. Maybe it's an installation or setup
issue, but I'm pretty knew to Python programming and don't know how to
debug this.

Lee Boger

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