Re: Speeding Computations

*To*: mathgroup at yoda.ncsa.uiuc.edu*Subject*: Re: Speeding Computations*From*: James Spottiswoode <uunet!compuserve.com!76446.564>*Date*: 13 Mar 90 22:06:58 EST

In reply to K. Suzuki, Mathematica is indeed a wonderfully rich and powerful language. But I doubt that it will ever have the speed of a lower level language like Fortran 77, even if a compiled version were produced. I am new to the language,but I have found a couple of things which speed up numerical analysis: Avoid extracting elements of a list below the top level. Transpose or Flatten to get the required elements to the 'top' level. Substitute dot products for summing operations where possible, e.g. x = Table[i,{i,100}]; y = x; Sum[x[[i]] y[[i]],{i,100}]//Timing {0.7 Second, 338350} x.y //Timing {0.1 Second, 338350} Has anyone any other advice for speeding the thing up, except faster hardware???