Hi Dave, Maybe we could take this thread off of gsl-help? Your issues seem more related to statistics and C programming, and less with the GSL.
I'll be happy to help you via personal correspondance. James On Wed, Dec 21, 2005 at 04:22:57PM -0600, David Eric Miller wrote: > Hi James, > > You are quite correct. I am attempting to do a Chi Squared > minimization > parameter estimation. I did not put all of the necessary pieces > into > my previous email since I was just starting to figure out how to > use gsl. > > If you could take a look at my last posting, I have a more > complete > test program which I am trying to get working. > > Thanks again. > > -dave miller > > > On Tue, 20 Dec 2005 15:59:26 -0600, James Bergstra > <[EMAIL PROTECTED]> wrote: > > >>> >I need to fit a Gaussian function to an array of data points. > >>> > >>>What is the nature of your data? Are they just X values or X,Y > >>pairs? > > > >>The data consists of (x, y) pairs with an associated error on y. > > > >Ok, so you are doing what is called parametric model estimation. > >Your model of > >y-given-x is a gaussian with some parameters, and you want to > >know what are > >those parameters. The way to use the function minimizers to get > >those > >parameters is to define a differentiable LOSS FUNCTION. This > >loss function will > >say for each (x,y) of data, how bad a given parameter is. You > >want to find the > >parameter such that the total loss over all your points is the > >smallest. > > > >The problem with your initial posting was that there was no loss > >function to be > >seen, and none of the functions you wrote was the one to > >minimize! > > > >A textbook on statistical inference can give you a better sense > >of what is going > >on. (check out Wasserman's "All of Statistics", or Bishop's > >book on neural > >networks.) > > > >James > > > > > > > _______________________________________________ > Help-gsl mailing list > [email protected] > http://lists.gnu.org/mailman/listinfo/help-gsl -- james bergstra http://www-etud.iro.umontreal.ca/~bergstrj _______________________________________________ Help-gsl mailing list [email protected] http://lists.gnu.org/mailman/listinfo/help-gsl
