On Sun, 09 Jan 2005 14:11:31 -0500, Phil Steitz <[EMAIL PROTECTED]> wrote:
... I would not be averse to adding either a set of static methods on double[] arrays or a RealVector class for various vector products, linear combinations, etc. if others have practical uses for this.
Regarding practical uses: I started working on a MultipleLinearRegression class (with m explaining variables and n observations) and the process derived from the formula of calculating the coefficients vector has some repetative code for mutliplying vectors by scalars as well as adding/subtracting/averaging vectors. The formulas (which also require inverting a matrix and matrix*vector opreation by the way) can be found, if in simplified forms, on the Dr. Math site: http://mathforum.org/library/drmath/view/51892.html
I would be happy to review and work with you on patches supporting vector operations directly. Regarding the application above, however, see the discussion here:
http://nagoya.apache.org/eyebrowse/[EMAIL PROTECTED]&msgId=1330648
The formulas that you cite look correct mathematically, but unfortunately not the best numerically. The reference in the post above describes a better computational approach. Patches to support QR decomposition of real matrices so we can implement that algorithm or other numerically sound multiple regression approaches would be appreciated.
Phil
--------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
--------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
