Re: Compiled programs

*To*: mathgroup at smc.vnet.net*Subject*: [mg14147] Re: [mg14111] Compiled programs*From*: "Jens-Peer Kuska" <kuska at linmpi.mpg.de>*Date*: Mon, 28 Sep 1998 18:57:13 -0400*Sender*: owner-wri-mathgroup at wolfram.com

Hi Miguel, at first keep in mind Mathematica is a computer algebra system. Its power are symbolic computations not numerical ones. If have written a book about Mathematica & C and I can tell You that the speed gain is a factor 10 for Mathematica Code to compiled Mathematica and again a factor of 10 from compiled Mathematica code to a MathLink program. The last value depends on the - ratio of I/O values to operations - the operating system - the overhead of the data Typical I found a speed up of a factor 100 and more when I use a MathLink program instead of pure Mathematica code. If You have to calculate a single function, that takes one value and returns one value You can have s slow MathLink program when You only implement x+1, because the overhead to tansfer the data will eat up all speed, and You can have a fast MathLink program when You have to perform some hundered operations with the data. Hope that helps Jens -----Original Message----- From: Miguel <migdie at encomix.es> To: mathgroup at smc.vnet.net Subject: [mg14147] [mg14111] Compiled programs >Hi all, > >This is the first time I post here. >I would like to know if anybody has used Mathematica to make a fast >program as is done in Fortran or C. I have read that the time of >computation is similar for C and Mathematica when you use compiled >functions. >Is this correct or Fortran and C are much faster than Mathematica ? (of >course it is when you use real number and not infinite precision...) >This is my big problem with Mathematica: It is too slow !! > >Thanks for all, >Miguel. > >Email : migdie at encomix.es > > >