Re: how to build pattern for a square matrix of reals?

*To*: mathgroup at smc.vnet.net*Subject*: [mg98396] Re: how to build pattern for a square matrix of reals?*From*: Albert Retey <awnl at gmx-topmail.de>*Date*: Thu, 9 Apr 2009 05:51:27 -0400 (EDT)*References*: <grhp95$mj7$1@smc.vnet.net>

sagrailo at gmail.com wrote: > As in subject: how to build a pattern that will specify that given > argument of a function has to be square matrix of reals? Tried with > following for "square matrix" part: > f[x_?MatrixQ[#] && Dimensions[#][[1]] == Dimensions[#][[2]] > &] := ... > but it doesn't seem to be working... > > Thanks. you are just missing some brackets: f[x_?((MatrixQ[#] && Dimensions[#][[1]] == Dimensions[#][[2]]) &)] := "match" hth, albert