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

*To*: mathgroup at smc.vnet.net*Subject*: [mg98402] Re: [mg98379] how to build pattern for a square matrix of reals?*From*: Adriano Pascoletti <adriano.pascoletti at dimi.uniud.it>*Date*: Thu, 9 Apr 2009 05:52:34 -0400 (EDT)*References*: <200904080903.FAA23145@smc.vnet.net>

Add an ampersand and a couple of parentheses: In[1]:= f[(m_)?(MatrixQ[#1, NumericQ] && SameQ @@ Dimensions[#1] & )] := "Good!" In[2]:= f[RandomReal[{-1, 1}, {2, 2}]] Out[2]= "Good!" In[3]:= f[RandomReal[{-1, 1}, {2, 3}]] Out[3]= f[{{0.7458917724579508, -0.9549183202849245, 0.010947478301726044}, {-0.14117283873516007, 0.6198728660624302, 0.07598523139890823}}] Adriano Pascoletti 2009/4/8 <sagrailo at gmail.com> > 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. >

**References**:**how to build pattern for a square matrix of reals?***From:*sagrailo@gmail.com