Re: Manipulating a matrix
- To: mathgroup at smc.vnet.net
- Subject: [mg59331] Re: Manipulating a matrix
- From: "Peltio" <peltio at trilight.zone>
- Date: Sat, 6 Aug 2005 01:29:22 -0400 (EDT)
- References: <200508020442.AAA16742@smc.vnet.net> <dcplkm$6od$1@smc.vnet.net>
- Reply-to: "Peltio" <peltioNOSPAM at despammed.com.invalid>
- Sender: owner-wri-mathgroup at wolfram.com
"Adel Elsabbagh" wrote [snip] >want to drop the i1,i2,...in rows and j1,j2,...jn columns write: > >m = m[[Drop[ Range[n],{i1,i2,...,in} ], Drop[ Range[n],{j1,j2,...,jn} ] ]] Are you sure you didn't mean m = m[[ Delete[ Range[nrows], {{i1}, {i2}, ..., {in}} ], Delete[ Range[ncols], {{j1}, {j2}, ..., {jn}} ] ]] instead? Or has Drop's syntax changed in the latest versions? cheers, Peltio Invalid address in reply-to. Crafty demunging required to mail me. PS We could brew a procedure right here, right now: matDrop[m_, rowlist_, collist_] := Module[ {nrows, ncols}, {nrows, ncols} = Dimensions[m]; m[[ Delete[ Range[nrows], List /@ rowlist ], Delete[ Range[ncols], List /@ collist ] ]] ] e.g. matDrop[m,{1},{1}] (* drops first row and column *) matDrop[m,{1,3},{}] (* drops rows 1 and 3 *) matDrop[m,{},{2,4}] (* drops columns 2 and 4 *) matDrop[m,{1,3},{2,4}] (* drops rows 1 and 3 and columns 2 and 4 *)
- References:
- Manipulating a matrix
- From: "Ramier" <wissam2@online.fr>
- Manipulating a matrix