Re: *Matrix witihn matrix*
- To: mathgroup at yoda.physics.unc.edu
- Subject: Re: *Matrix witihn matrix*
- From: leszek (Leszek Sczaniecki)
- Date: Tue, 28 Jun 1994 10:32:26 -0500
> Date: Fri, 24 Jun 1994 18:16:55 -0700 > From: "Roger M. Jones" <rmj at llewelyn.slac.stanford.edu> > Subject: *Matrix witihn matrix* > To: mathgroup at yoda.physics.unc.edu > > I have a matrix containing sub-matrices which I wish to combine. > > I have implemented this as: > > CatMatrix[a_,b_,c_,d_]:=Block[{t1}, > t1=Length[a];Join[Table[Flatten[{a[[i]],b[[i]]}], > {i,1,t1}],Table[Flatten[{c[[i]],d[[i]]}], > {i,1,t1}]]]. > > So that: > > a={{a11,a12,a13},{a21,a22,a23},{a31,a32,a33}}; > b={{b11,b12,b13},{b21,b22,b23},{b31,b32,b33}}; > c={{c11,c12,c13},{c21,c22,c23},{c31,c32,c33}}; > d={{d11,d12,d13},{d21,d22,d23},{d31,d32,d33}}; > > {a,b,c,d}-----> > > {{a11, a12, a13, b11, b12, b13}, {a21, a22, a23, b21, b22, b23}, > > > > {a31, a32, a33, b31, b32, b33}, > > > {c11, c12, c13, d11, d12, d13}, > > > > {c21, c22, c23, d21, d22, d23}, {c31, c32, c33, d31, d32, d33}} > > Does anyone know of a simplier implementation? > In[6]:= << LinearAlgebra`MatrixManipulation` In[7]:= ?BlockMatrix BlockMatrix[block] returns a matrix composed of a matrix of matrices. In[8]:= a={{a11,a12,a13},{a21,a22,a23},{a31,a32,a33}}; In[9]:= b={{b11,b12,b13},{b21,b22,b23},{b31,b32,b33}}; In[10]:= c={{c11,c12,c13},{c21,c22,c23},{c31,c32,c33}}; In[11]:= d={{d11,d12,d13},{d21,d22,d23},{d31,d32,d33}}; In[12]:= BlockMatrix[{{a, b}, {c, d}}] Out[12]= {{a11, a12, a13, b11, b12, b13}, {a21, a22, a23, b21, b22, b23}, {a31, a32, a33, b31, b32, b33}, {c11, c12, c13, d11, d12, d13}, {c21, c22, c23, d21, d22, d23}, {c31, c32, c33, d31, d32, d33}} Leszek