C/C++ implementation of the Levenberg-Marquardt non-linear
least squares algorithm. levmar includes double and single precision LM versions, both
with analytic and finite difference approximated jacobians
The inverse of the gradient function. I ve provided versions that work on 1-d vectors, or 2-d or 3-d arrays. In the 1-d case I offer 5 different methods, from cumtrapz, and an integrated cubic spline, plus several finite difference methods.
In higher dimensions, only a finite difference/linear algebra solution is provided, but it is fully vectorized and fully sparse in its approach. In 2-d and 3-d, if the gradients are inconsistent, then a least squares solution is generated
Small utility which calculates the difference in hours and seconds between a starting time and finish time. Useful for calculating payroll hours, overtime, etc. with C source code. Freeware.
pdnMesh is an automatic mesh generator and solver for Finite Element problems. It will also do post-processing to generate contour plots and Postscript printouts. GUI support using GTK or MFC (Win32) is available. The problem definition can be done in any form and given to pdnMesh as an input data file. Drawing Exchange Format (DXF) files can be directly imported to pdnmesh. The quality and the coarseness of the mesh can be controlled by giving input parameters.