[SciPy-user] SystemError in optimize.bisplrep

[Martin Lüthi]

Hi

There is a consistent SystemError when I try to use optimize.bisplrep on a
certain data set.

=================

Python 2.4 (#1, Nov 30 2004, 09:18:19) 
[GCC 3.3.3] on linux2

help(scipy)   gives VERSION 0.3.2_302.4546  (CVS version from about January 20)

help(Numeric) gives VERSION 23.1

=================

numerix Numeric 23.1
 iopt,kx,ky,m= 0 3 3 16
 nxest,nyest,nmax= 9 9 9
 lwrk1,lwrk2,kwrk= 1298 571 20
 xb,xe,yb,ye=  1711.91585  1102.19325 -2237.94674 -1573.73858
 eps,s  1.E-16  10.3431458
Traceback (most recent call last):
  File "fehler.py", line 21, in ?
    xvelospl = scipy.interpolate.bisplrep(vc[:,0], vc[:,1], vc[:,2])
  File "/usr/local/lib/python2.4/site-packages/scipy/interpolate/fitpack.py", line 611, in bisplrep
    tx,ty,nxest,nyest,wrk,lwrk1,lwrk2)
SystemError: error return without exception set

==================

This code produces the error 

==================

import scipy

vc = scipy.array([[  1.71191585e+03,  -2.23794674e+03,   4.75308808e+00],
       [  2.12372140e+03,  -1.93888718e+03,   5.81923099e+00],
       [  3.35389426e+03,  -1.04998143e+03,   1.62242033e+00],
       [  2.94453166e+03,  -1.34979104e+03,   4.88224816e+00],
       [  2.53225224e+03,  -1.64269489e+03,   8.05746675e+00],
       [  2.23717430e+03,  -1.22890371e+03,   4.83692941e+00],
       [  1.35903071e+03,  -1.88168793e-02,   1.74331390e+00],
       [  1.65124228e+03,  -4.07642789e+02,   1.90797462e+00],
       [  1.89958300e+03,  -5.17000000e+02,   2.26234838e+00],
       [  1.40869886e+03,  -9.83926136e+02,   3.04278075e+00],
       [  1.69451200e+03,  -1.28935600e+03,   4.54354841e+00],
       [  1.73692665e+03,  -9.59722949e+02,   3.16536871e+00],
       [  2.49206700e+03,  -7.63554000e+02,   2.68046469e+00],
       [  2.14106300e+03,  -1.31310900e+03,   5.31786607e+00],
       [  7.18383558e+02,  -1.74427543e+03,   2.47771836e+00],
       [  1.10219325e+03,  -1.57373858e+03,   2.79857398e+00]])


spl = scipy.interpolate.bisplrep(vc[:,0], vc[:,1], vc[:,2])

==================

The error does not occur with different data.

Thanks for any help!

Martin

-- 
Martin Lüthi                 answer at tnoo.net