Re: [Mplapack-devel] possibly a bug in Cheev
Status: Pre-Alpha
Brought to you by:
nakatamaho
From: Maho N. <ch...@ma...> - 2012-08-10 22:43:27
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Hello From: Akira SaiToh <aki...@ni...> Subject: Re: [Mplapack-devel] possibly a bug in Cheev Date: Sat, 11 Aug 2012 01:25:28 +0900 > Hello, Nakata-san, > > Thank you for your effort. With your patch, I could get > correct eigenvalues for the previous examples. However, I Congratulations! > encountered another problem. Ah :-( I'm sorry to hear that. > For the matrix > > 2 0 1 > 0 2 0 > 1 0 2 > > Cheev returns correct eigenvalues, 1, 2, and 3. Then, for > the matrix > > 20 0 10 > 0 20 0 > 10 0 20 > > expected eigenvalues are 10, 20, and 30. However, Cheev > returns 20, 20, and 20. I guess probably Cheev should be > modified so that an appropriate scaling is internally > performed. Yes, many thanks for your bug report. I'll fix hopefully soon. Thanks Nakata Maho > ------------------------------------------------------- > [saitoh@localhost test_cheev]$ LD_LIBRARY_PATH=/usr/local/lib ./a.out > 2 0 1 0 2 0 1 0 2 > A = > 2 0 1 > 0 2 0 > 1 0 2 > Eigenvalues: > 1 2 3 > Unitary matrix: > 0.707107+i*0 0+i*0 0.707107+i*0 > 0+i*0 -1+i*0 0+i*0 > -0.707107+i*0 0+i*0 0.707107+i*0 > [saitoh@localhost test_cheev]$ LD_LIBRARY_PATH=/usr/local/lib ./a.out > 20 0 10 0 20 0 10 0 20 > A = > 20 0 10 > 0 20 0 > 10 0 20 > Eigenvalues: > 20 20 20 > Unitary matrix: > -1+i*0 4.85181e-173+i*0 0+i*0 > 0+i*0 -1+i*0 0+i*0 > 0+i*0 0+i*0 1+i*0 > ------------------------------------------------------- > > Regards, > Akira SaiToh > |