Re: symbolic matrix calculation doesn't work

• To: mathgroup at smc.vnet.net
• Subject: [mg56374] Re: [mg56368] symbolic matrix calculation doesn't work
• From: "Florian Jaccard" <florian.jaccard at he-arc.ch>
• Date: Sat, 23 Apr 2005 01:16:06 -0400 (EDT)
• Sender: owner-wri-mathgroup at wolfram.com

Hello  Jack !

First problem :

If you want T to be a 2x2 matrix, you have to first assign T={{ ... }} , and
afterward you can have a look at the MatrixForm of T.
So you have to write :  (T=...)//MatrixForm, or MatrixForm[T=...] , or
T=...;MatrixForm[T] , but not T=...//MatrixForm, because T would be
considered as the matrixform display of your matrix, and not as the matrix
itself.

Second problem :

d is not a matrix, but a vector. So it cannot be transposed. If you want d
to be a 2x1 matrix, you have to write d={{..},{..}} !

So here a corrected code :

In[1]:=
MatrixForm[T = (-(2*u)^(-1))*{{1, 1}, {1, 1}}]

In[2]:=
MatrixForm[d = {{En1}, {In1}}]

In[3]:=
MatrixForm[P = {{0, 1}, {1, 0}}]

In[4]:=
a = (1/2)*Inverse[P - T . P . Transpose[Conjugate[T]]] . d .
Transpose[Conjugate[d]]

In[5]:=
MatrixForm[a]

Last tip : Avoid capital letters...

Regards

F.Jaccard

-----Message d'origine-----
De : Jack [mailto:jack.peng at gmail.com]
Envoyé : ven., 22. avril 2005 12:26
À : mathgroup at smc.vnet.net
Objet : [mg56368] symbolic matrix calculation doesn't work

Hi,
I am new to Mathematica and I can't seem to get mathematica to