Re: [Maxima-discuss] submatrix assignment ala Matlab

[德馬堤 <d00...@nt...>]

Thank you, the following function does it:


submat(M,rows,cols):= block(
rows:subst(length(M),end,rows),
cols:subst(length(M[1]),end,cols),
transpose(apply(matrix,makelist(transpose(apply(matrix,makelist(M[i],i,rows[1],rows[2])))[j],j,cols[1],cols[2]))))$


For example:

M:matrix([12, 3, 3],[2, 3, 4]);
submat(M,[1,2],[1,2]);            /* submat(matrix,[minrow, maxrow],[mincol,maxcol])  */

submat(M,[1,end-1],[1,end-2])