# potfit wiki

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maxchfile

# Maxch file

This file can be used to limit the changes in the tabulated version of the Powell algorithm. If a change greater than this value is about to be done, this change is dismissed and the inner loop of the algorithm is restarted.

For other algorithms and analytic potentials this file is ignored.

#### Format

The maxchfile has to be given in the following format:

a_1
a_2
a_3
...
a_n

where $a_i$ is the maximum change that is allowed for this parameter. There has to be a line for every parameter in your tabulated potential.

Set $a_k$ to 0 to disable it for the $k^{\text{th}}$ parameter.