Re: Matrix Manipulation: deletion of rows and columns
- To: mathgroup at smc.vnet.net
- Subject: [mg49301] Re: Matrix Manipulation: deletion of rows and columns
- From: BobHanlon at aol.com
- Date: Tue, 13 Jul 2004 04:32:32 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
dropCol[mat_List?(!VectorQ[#]&), colNbr_Integer] := Drop[#, {colNbr}]& /@ mat; dropCol[mat_List?(!VectorQ[#]&), colNbr_?VectorQ] := Fold[dropCol[#1,#2]&, mat, Sort[Union[colNbr], Greater]]; dropRow[mat_List?(!VectorQ[#]&), rowNbr_Integer] := Drop[mat, {rowNbr}]; dropRow[mat_List?(!VectorQ[#]&), rowNbr_?VectorQ] := Fold[dropRow[#1,#2]&, mat, Sort[Union[rowNbr], Greater]]; mat1 = Array[a, {7,7}]; dropRow[dropCol[mat1,{1,4,5,7}],{2,3,4,6}] {{a[1, 2], a[1, 3], a[1, 6]}, {a[5, 2], a[5, 3], a[5, 6]}, {a[7, 2], a[7, 3], a[7, 6]}} Bob Hanlon > In a message dated Mon, 12 Jul 2004 06:26:28 +0000 (UTC), > mbekkali at gmail.com writes: Is there a way to delete rows or/and columns of a > matrix, say delete > rows 2,4 and 6,17 of 20x20 matrix and form a new matrix from the > remaining rows and columns. >