Re: It would be nice to have DiagonalMatrix accept a matrix as building

*To*: mathgroup at smc.vnet.net*Subject*: [mg113547] Re: It would be nice to have DiagonalMatrix accept a matrix as building*From*: "Nasser M. Abbasi" <nma at 12000.org>*Date*: Tue, 2 Nov 2010 05:01:11 -0500 (EST)*References*: <iajcai$p6j$1@smc.vnet.net> <iam31c$jts$1@smc.vnet.net>*Reply-to*: nma at 12000.org

On 11/1/2010 2:59 AM, Sjoerd C. de Vries wrote: > What's common for you may be rare for someone else. Personally, in the > last 20 or so years I've never encountered the need for such a > function. Then you must not work in the same as I do? This is very common in building the system matrix for finite difference schemes for example where many matrices have banded blocked structure. > So, I'd say it seems a bit unreasonable to demand that Where did this "demand" come from? Where did I demand anything? Look at the title. I said "it would be nice". How did you change this to "demand" I have no idea. You must use a different dictionary. > Wolfram should do this or that because you yourself are in need of a > certain function, particularly when it is so easy to write > > diagonalMatrix[mat_?MatrixQ, n_] := > Module[{m}, > dm = DiagonalMatrix[Table[m, {n}]]; > ArrayFlatten[dm /. m -> mat] > ] > > diagonalMatrix[{{1, 2, 5}, {3, 4, 5}}, 10] // MatrixForm > > Cheers -- Sjoerd > You could have provided the answer above, without all that unnecessary editorial lecturing. --Nasser