Re: evaluating functions and displaying results numerically

*To*: mathgroup at smc.vnet.net*Subject*: [mg126262] Re: evaluating functions and displaying results numerically*From*: Murray Eisenberg <murray at math.umass.edu>*Date*: Fri, 27 Apr 2012 06:52:42 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <201204260932.FAA05740@smc.vnet.net>*Reply-to*: murray at math.umass.edu

Kindkly post your code about the sum directly in an e-mail message (and be sure to use Copy As...Plain Text from Mathematica). Trying to deal with code shown just in a pdf is not easy. On 4/26/12 5:32 AM, Alexei Boulbitch wrote: > Thanks for the replies. I can go along with all your explanations for the Sin function, even though I havent had this interpretation of results from Mathematica before. I never had to use the N option before. What about my second enquire, reproduced below: > > In another instance, I have a summation of about 1000 terms defined as > > a function of 3 arguments. When I use numerical arguments to calculate the summation, instead of > > Mathematica calculating a numerical result it generates a symbolic > > output with all 1000 terms. > > It doesnt make sense that Mathematica chooses to do the whole thing symbolically. I have made similar calculations before, and Mathematica performed the calculation numerically. I presume that I have enabled some sort of symbolic calculation mode, but I cannot figure out where. I am attaching a a link to a pdf file showing a image of the generated result for my function called "Absorption". The other functions called by Absorption are defined prior to the definition of Absorption. I just want to show the type of result generated. Also, If I want to plot my function Absorption relative to one of the arguments, Mathematica just doesnt plot it. > > Best regards > > The output image is in the google docs file below > > https://docs.google.com/open?id=0Bw08G8QtolpXUDBnQUswdXUyVE0 > > > > It looks possible that you have some function or variable in your sum that has not been defined before and, therefore, Mathematica treats the whole thing analytically. >> From the fragment you showed in the link it was difficult to see which one it could be. May be Ref? > If you write your functions directly in the post, it will be easier to help you. > > Have fun, Alexei > > Alexei BOULBITCH, Dr., habil. > IEE S.A. > ZAE Weiergewan, > 11, rue Edmond Reuter, > L-5326 Contern, LUXEMBOURG > > Office phone : +352-2454-2566 > Office fax: +352-2454-3566 > mobile phone: +49 151 52 40 66 44 > > e-mail: alexei.boulbitch at iee.lu<mailto:alexei.boulbitch at iee.lu> > > > -- Murray Eisenberg murray at math.umass.edu Mathematics & Statistics Dept. Lederle Graduate Research Tower phone 413 549-1020 (H) University of Massachusetts 413 545-2859 (W) 710 North Pleasant Street fax 413 545-1801 Amherst, MA 01003-9305

**References**:**Re: evaluating functions and displaying results numerically***From:*Alexei Boulbitch <Alexei.Boulbitch@iee.lu>