# The Jacobian Panel

### The Pisces Jacobian Panel.

The Jacobian panel allows the user to set parameters used by Pisces
for taking numerical derivatives and for finding roots.
The top of the Jacobian panel contains fields that determine how
Pisces computes finite-difference derivatives.

The remainder of the panel determines stopping criteria for Newton's
methods of finding roots.

**epsi_func**
- If the norm of the model evaluated at a point
*x*
is less than the value of this field, then *x*
is determined to be a zero of the model.
**epsi_vars**
- During Newton's method, if the size of the Newton step distance
is less than the value of this field, then
we stop Newton's method because we are
either not converging to a root or are converging very slowly.
**newt_step**
- The value of this field determines the number of
Newton steps we are allowed to take before deciding that an
initial guess will never converge to a root.

**Important:** after making a change to the Jacobian panel, you
**must** press the "Update" button,
or your change will not be implemented!

**Next: **The Derived Model Panel

**Previous: **User Interface

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Comments to: pisces@geom.umn.edu

Last modified: Sun Nov 26 18:51:10 1995

Copyright © 1995 by
The Geometry Center,
all rights reserved.