Student Support Forum > General > > "Help with creating matrix from another matrix"

 Post Reply: Name: Email Address: Please send email when my message is replied to. Url (optional): Subject: Message: view original message? Attachment (optional): Please answer this: 1+3 =

 Original Message (ID '450038') By Anton Siswo: In Response To 'Re: Re: Re: Re: Re: Re: Re: Help with creating ...' --------- It's square matrix. So, the blank under diagonal matrix are same values. so [1,2]with[2,1] have same value. so does with [5,6] and [6,5]. for the column 13 and row 1..6 which zero in my spreadsheet, look at your code, [1,13] should be zero, but you write it [nonzero]. do not search the whole matrix values in [16x24], but search it each rows and finished before moving into another rows. then, for first rows, the only value are starting from [1,1]....[1,150],[2,1]....[2,150],[3,1]....[3,150] until [42,1]....[42,150] which only for the first row and the value of this row are the non zero value in my spreadsheet. actually, this code below maybe could help us. this code wasnt come from mathematica. it already sum the [150x150] matrix but only for upper triangle of square matrix. is there any way to transform this code into mathematica? as you see, the table in my spreadsheet are for upper triangle square matrix. for k in [1..16] do for i in S[k] do for j in S[k] do if i<=j then B[i][j]:=B[i][j]+A[Position(S[k],i)][Position(S[k],j)];