Hello,

I am the creator of the Mantissa library (http://www.spaceroots.org/software/mantissa/index.html), a Java library providing some mathematical algorithms.

Mantissa provides several algorithms that could be useful for Commons-Math. I think the objectives of the two libraries are quite similar, but I don't know (yet) the point were you consider "commons problems" addressed by Commons-Math end and where problems are considered too specific to be provided here.

I would be very glad to donate parts of Mantissa code to Commons-Math if you wish so. Mantissa is released under a revised-BSD type license, but I am quite happy with Apache license too and ready to change.

I don't think everything in Mantissa is useful for Commons-Math. IMHO, the most interesting parts are :

 - the estimation package
   Gauss-Newton estimator (based on LU decomposition),
   Levenberg-Marquardt estimator (based on QR decomposition)
 - the fitting package (curve fitting, using the estimation package)
 - the Ordinary Differential Equations package
   this is clearly THE best package in Mantissa, with several
   state of the art integrators with fixed steps, variable stepsize
   (including Dormand-Prince 8 (5,3) and Gragg-Bulirsch-Stoer),
   all of them supporting continuous output and multiple switching
   functions (can be used for G-stop, but not limited to that), well
  tested and used
 - the roots package
  provides a Brent algorithm when the derivatives are not available


Some package that may be interesting are :

- the geometry package
  mainly for the 3D rotations implementations using quaternions
  internally and axes/angles, Cardan angles, Euler angles, matrices,
  single or double vectors pairs and quaternions in the interface
- the functions package
  providing notions like computable or sampled functions
- the quadrature package
  (Riemann, trapezoid, enhanced Simpson, Gauss-Legendre up
   to 5 points, easily extended)
- the utilities package
  for the array mapping paradigm

Some package that are probably not interesting are :

- the algebra package
  orthogonal polynomials, inefficient and awkward implementation
- the raw linear algebra package
  basic implementation developped for speed ... not sure the goal was
  achieved and using only straightforward algorithms, not state of the art
- the random number generators
  supports correlated vectors generation


---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]

Reply via email to