[SciPy-user] problem with odeint
Ryan Krauss
ryanlists at gmail.com
Thu Mar 2 17:32:05 EST 2006
I am having a problem with odeint. My integration runs o.k. if I
choose a fairly short time interval, but when I set the maximum value
for my t vector higher than about 1 second, I get this message:
In [178]: run sweptsine_ode.py
lsoda-- at t (=r1), too much accuracy requested
for precision of machine.. see tolsf (=r2) ls
in above, r1 = 0.5448183650273E+00 r2 = NAN
Excess accuracy requested (tolerances too small).
Run with full_output = 1 to get quantitative information.
Running with fulloutput produces:
{'hu': array([ 0.00020682, 0.00043534, 0.00043534, ..., 0. ,
0. , 0. ]),
'imxer': -1267232872,
'leniw': 23,
'lenrw': 68,
'message': 'Excess accuracy requested (tolerances too small).',
'mused': array([1, 1, 1, ..., 0, 0, 0]),
'nfe': array([19, 27, 31, ..., 0, 0, 0]),
'nje': array([0, 0, 0, ..., 0, 0, 0]),
'nqu': array([2, 3, 3, ..., 0, 0, 0]),
'nst': array([ 9, 13, 15, ..., 0, 0, 0]),
'tcur': array([ 0.00106956, 0.00235387, 0.00322454, ..., 0. ,
0. , 0. ]),
'tolsf': array([ 7.88983883e-314, 7.88983883e-314, 7.88983883e-314, ...,
0.00000000e+000, 0.00000000e+000, 0.00000000e+000]),
'tsw': array([ 0., 0., 0., ..., 0., 0., 0.])}
The script is attached and should be self contained. Messing with
atol and rtol doesn't seem to help, so I don't know what the message
about requested accuracy means.
Any help/direction in fixing this would be appreciated.
Thanks,
Ryan
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