Did you consider using the traced package?
2009/12/24 Bas van Dijk <v.dijk....@gmail.com>: > On Thu, Dec 24, 2009 at 1:00 AM, Andrey Sisoyev > <andrejs.sisoj...@nextmail.ru> wrote: >> Where do you make use of it? :) > > A few months ago I was working on 'levmar'[1] a Levenberg-Marquardt > data fitting library in Haskell. If you want your data fitting to be > really fast you need to supply a Jacobian of the model function you > want to fit. A Jacobian describes the partial derivatives of the > parameters of the model function. I used Conal Elliott's > vector-space[2] library to automatically derive a Jacobian from the > model function. > > I was interested in the derivatives vector-space would come up with. A > derivative however, is just a function so the only thing you can do > with it is apply it to a value. This then yields a result which is > usually just a Double. I wasn't really interested in this actual > numeric result but more in the underlying numeric expressing that > generated that result. > > So I wrote repr to visualize this numeric expression. However, after I > wrote repr, the work on levmar stalled a bit and I did not actually > get around to applying repr to the derivatives. I plan to make a new > release of levmar in the coming weeks or so and I think I will use > repr then. > > regards, > > Bas > > [1] http://hackage.haskell.org/package/levmar > [2] http://hackage.haskell.org/package/vector-space > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
