On Wednesday 09 January 2002 06:50 am, S.D.Mechveliani wrote: > Zhe Fu <[EMAIL PROTECTED]> writes > > > Is there any built-in functions in Haskell to implement > > diffential operation and partial diffential operation? > > Or can anyone give me some advices about how to implement them > > with Haskell? Thanks. > > There are no differential operators in Haskell-98 standard library, > nor even polynomial arithmetic. > Very probably, there exist application programs treating > differential operators. Try to search in http://www.haskell.org > > If you are going to implement differential operators, > try first to implement, for example, polynomial multiplication. > After this, differentiation would not look hard. > But it depends on what one wants to differentiate, one has to > formulate first what kind of expressions are supposed to be > differentiated. >
how about this: diff f x = (f (x + epsilon) - f (x - epsilon)) / (2 * epsilon) where epsilon = 0.00001 every call to say "diff sin" will cost you about as much as every call to "sin" HTH Alec _______________________________________________ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell