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)*Reply-to*: <florian.jaccard at he-arc.ch>*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 multiply symbolic matrices. Can anyone please help? The notebook file is at http://www.eecs.berkeley.edu/~xpeng/question/ Thank you so much. Please reply to xpeng at eecs.berkeley.edu. Jack