*To*: mathgroup@smc.vnet.net*Subject*: [mg10315] Re: question*From*: danl@wolfram.com (Daniel Lichtblau)*Date*: Mon, 5 Jan 1998 22:24:32 -0500*Organization*: Wolfram Research, Inc.*References*: <687po8$1jc@smc.vnet.net>

In article <687po8$1jc@smc.vnet.net> "=?big5?B?p0WuYbvK?=" <g8673007@cc.nchulc.edu.tw> writes: > > I found that Mathematica may deal poorly with the orthogonal matrix > problem. Just as below shows, I can not solve my problem using > Mathematica. Maybe you have right way to finish it, I think and hope > so. If it is true, excuse me, I would thank you to let me know the > answer. > > Following is my input and output in Mathematica: a={{1,2},{3,4}} > {{1, 2}, {3, 4}} > p={{a11,a12},{a21,a22}} > {{a11, a12}, {a21, a22}} > ans=Solve[Transpose[p].a.p==IdentityMatrix[2]] {} > > Thank you ! > Happy New Year ! > Char-Ming Yu, > Department of Economics, > National Chung Hsing Univerisy, > Taipei, Taiwan > It is correct that the solution set is empty. Note that the right-hand-side of the matrix equation is symmetric while the left-hand-side is not (which is a good indication that the equations are inconsistent, because now the system is overdetermined). Daniel Lichtblau Wolfram Research