FITPACK (Dierckx) - provenance and redistribution
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The Fortran sources in this directory are FITPACK, a package for curve and
surface fitting with splines by Paul Dierckx (Department of Computer Science,
KU Leuven), distributed through netlib (https://netlib.org/dierckx/). The
double-precision ("ddierckx") variant vendored here was generated from the
netlib sources by Pearu Peterson.

FITPACK carries no separate license text. Dierckx released it as freely
available software through netlib, and it has long been redistributed on that
basis; SciPy, among other projects, incorporates the same sources. It is used
and redistributed here on those terms. FITPACK is described in:

    P. Dierckx, Curve and Surface Fitting with Splines,
    Monographs on Numerical Analysis, Oxford University Press, 1993.

Local edit (2026-08-01)
-----------------------

Twelve smoothing fitters (curfit, percur, parcur, clocur, concur, regrid,
parsur, pogrid, spgrid, sphere, surfit, polar) take `tol` and `maxit` as
trailing arguments rather than setting them as locals, so a caller can reach
them. Each edited file records the change and the original values in a comment
in place of the removed assignments. No `fp*` worker signature changed, and an
unchanged call is an unchanged computation. See README in this directory.
