gdl-mpfit - 1.85+2017.01.03-4 main

These GDL routines provide a robust and relatively fast way to perform
least-squares curve and surface fitting. The algorithms are translated from
MINPACK-1, which is a rugged minimization routine found on Netlib, and
distributed with permission. This algorithm is more desirable than CURVEFIT
because it is generally more stable and less likely to crash than the
brute-force approach taken by CURVEFIT, which is based upon Numerical
Recipes.
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MPFIT has additional capabilities not found in CURVEFIT. Model parameters can
be "frozen" (that is, held constant during the fitting process). Simple
boundary constraints can be imposed on parameter values, which can be helpful
to keep parameters from becoming negative, for example. Please see the
documentation for the PARINFO keyword if you wish to use this facility.