Modeling and Array Problem

*To*: mathgroup at smc.vnet.net*Subject*: [mg59151] Modeling and Array Problem*From*: ulenia <ulenia at yahoo.com>*Date*: Sat, 30 Jul 2005 01:25:34 -0400 (EDT)*References*: <dbd0pv$2qu$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Hello! I have some (I am sure) small problems with understanding of array modulation and loops in Mathematica. I read i- amount of images ({i,1,Length[list1]} from my work-directory. I do some calculations in loops, a cause of big amount of images. For Example: >Do[z[i]=Chop[DFT[image[i]]-DFT[image[i+1]],10-4],{i,Length[list]-1}] Some of parameters I need depends from an image, for example: a[i] and b[i] or: >Do[m1[i]=Dimensions[image[i]][[1]], ],{i,Length[list]}] >Do[m2[i]=Dimensions[image[i]][[2]], ],{i,Length[list]}] I am going to do for every matrix-element [[k,l]] of z[i]: >Do[z[i][[k,l]]=z[i][[k,l]]/((k*a[i])^2+( k*a[i])^2) ,{k,1,m1[i]},{l,1,m2[i]}, {i,Length[list]-1}] Unfortunately I get a following error message: Set : : setps: z[i] in assignment of part is not a symbol â?¦â?¦â?¦â?¦â?¦â?¦â?¦â?¦â?¦â?¦â?¦â?¦â?¦â?¦â?¦â?¦â?¦â?¦â?¦â?¦â?¦â?¦â?¦â?¦â?¦â?¦â?¦â?¦. General : : stop : Further output of Set : : setps will be suppressed during this calculation. I have no idea, what shoul I do. I have done it for separate matrix elements [[1,2]] of matrix i=1:: >z[1][[1,2]]/((1*a[1])^2+( 2*a[1])^2) I get a very nice result: >8.59575x10-7 + 1.07787x10-6 i Why I can not calculate it with do-loop forevery k und l element of i-amount of matrix? I would appreciate any help. Thank you very much and have nice weekend. Ula ulenia at yahoo.com