On Fri, 13 Aug 1999, Rene Grognard wrote: > My question is therefore: is Haskell at all suitable for complex numerical > applications ? _In my opinion_, Haskell is suitable for numerical programming if you don't need performance close to C (because your problems are small say and you're prototyping) or the numerical portions of your algorithms are sufficiently stable (e.g., root finding, SVD decomposition, etc) that you can code them once in C and then call them from Haskell code that does `the interesting part of the algorithm'. However it's not (yet?) suitable for writing numerical algorithms where the performance needs to be close to C simply to be feasible (e.g., solving large MRF models, etc). The `yet' comes from the observation that (AFAIK) there's no fundamental reason why a such algorithms couldn't be programmed in a functional way & compiled to something close to C since the patterns of computation are in many ways much simpler than in less numerical algorithms. Of course detecting these patterns at compile time is much tougher than it looks at first glance. > Is there even any interest for such applications in the Haskell community ? Well... here's a few indincations (sorry no URLs) that there is interest in programming numerical algorithms in Haskell. (1) I'm interested in (semi-)numerical algorithms in Haskell, but it doesn't have the performance (yet?) to program the numerical bits in Haskell. Unfortunately the numerical bits are, for my application, the difficult & rapidly changing, bit so writing them in C and then calling that from Haskell means I wouldn't get any `programmer efficiency' benefit. (2) Jerzy Karczmarczuk (spelling from memory) has written a renderer in Haskell (as did one of John Hughes students at Chalmers, but that looks to be written in non-standard Haskell). John O'Donnell was looking at expressing rendering algorithms in Haskell as well I think. (3) Jan Skibinski has written some packages doing some linear algebra stuff, and seems a strong proponent of making Haskell better equipped for such problems with standard libraries. The noticeable thing though is that I don't think any of these people work on numerical algorithms in Haskell `full time', as it were. > If the answers are yes, are there books or on-line tutorials giving > non-trivial examples of such uses ? ... libraries ? Not that I know of. Hope this helps, ___cheers,_dave______________________________________________________ email: [EMAIL PROTECTED] "He'd stay up all night inventing an www.cs.bris.ac.uk/~tweed/pi.htm alarm clock to ensure he woke early work tel: (0117) 954-5253 the next morning"-- Terry Pratchett
