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## More Neural Network musings..

**From**: |
John Utz |

**Subject**: |
More Neural Network musings.. |

**Date**: |
Thu, 30 Nov 1995 12:47:02 -0800 (PST) |

Hi gang;
As i mentioned in my previous letter, i am trying to use octave
to solve dynamical systems and neural network problems.
Both of these items are variations on systems of differential
equations.
One of the key techniques in looking at simple dymanical systems
is the use of the phase plane. The phase plane display of a dynamical
system will include locations called singularities. Singularities seem to
present a problem for a numerical solver such as lsode and dassl.
The problem with singularities is that they are the points in
which a function under analysis will equal zero in the numerator ( not
unusual in any way ) and 0 in the *denominator* ( this is usually
construed as a Bad Thing (tm) ).
the following is exerted from octave's online manual:
{
The function `dassl' can be used Solve DAEs of the form
0 = f (x-dot, x, t), x(t=0) = x_0, x-dot(t=0) = x-dot_0
dassl (FCN, X_0, XDOT_0, T_OUT, T_CRIT)
...
The fifth argument is optional, and may be used to specify a set of
times that the DAE solver should not integrate past. It is useful for
avoiding difficulties with singularities and points where there is a
discontinuity in the derivative.
}
Well, heck. In my case, i wish to eagerly seek out
discontinuities and singularities! Worse yet. I want to plot them!
Has anybody had any experience with this that they would like to
share with me?
*******************************************************************************
John Utz address@hidden
idiocy is the impulse function in the convolution of life

**More Neural Network musings..**,
*John Utz* **<=**