Re: evaluating functions and displaying results numerically

*To*: mathgroup at smc.vnet.net*Subject*: [mg126243] Re: evaluating functions and displaying results numerically*From*: Alexei Boulbitch <Alexei.Boulbitch at iee.lu>*Date*: Thu, 26 Apr 2012 05:32:44 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

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>

**Follow-Ups**:**Re: evaluating functions and displaying results numerically***From:*Murray Eisenberg <murray@math.umass.edu>