Flattening a hypermatrix into an ordinary matrix

*To*: mathgroup at smc.vnet.net*Subject*: [mg126710] Flattening a hypermatrix into an ordinary matrix*From*: carlos at colorado.edu*Date*: Fri, 1 Jun 2012 05:19:24 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

I have an n x n hypermatrix, the entries of which are m x m blocks. For example A below (m=3, n=2): A11={{B11,B12,B13},{B21,B22,B23},{B31,B32,B33}}; A12={{C11,C12,C13},{C21,C22,C23},{C31,C32,C33}}; A21={{D11,D12,D13},{D21,D22,D23},{D31,D32,D33}}; A22={{E11,E12,E13},{E21,E22,E23},{E31,E32,E33}}; A={{ A11,A12},{A21,A22}}; I want to convert this to an ordinary n*m x n*m matrix. For the example I want A to become {{B11,B12,B13,C11,C12,C13},{B21,B22,B23,C21,C22,C23}, {B31,B32,B33,C31,C32,C33},{D11,D12,D13,E11,E12,E13}, {D21,D22,D23,E21,E22,E23},{D31,D32,D33,E31,E32,E33}} This can be easily done with C style loops as AA=Table[0,{m*n},{m*n}]; For [i=1,i<=n,i++, For[j=1,j<=n,j++, For [k=1,k<=m,k++, For [l=1,l<=m,l++, AA[[m*(i-1)+k,m*(j-1)+l]]=A[[i,j,k,l]] ]]]]; but is there a more elegant way using Flatten? (Flatten[A,1] doesnt do it.) It should work also for blocks of varying size for future use.

**Follow-Ups**:**Re: Flattening a hypermatrix into an ordinary matrix***From:*Bob Hanlon <hanlonr357@gmail.com>

**Re: Flattening a hypermatrix into an ordinary matrix***From:*Andrzej Kozlowski <akozlowski@gmail.com>

**Re: Flattening a hypermatrix into an ordinary matrix***From:*Sseziwa Mukasa <mukasa@gmail.com>