Re: [Mplapack-devel] Can I compute eigenvalues of ill-conditioned matrix less than 10^-156 ?
Status: Pre-Alpha
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From: Maho N. <ch...@ma...> - 2011-09-13 03:53:21
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From: Gang Yan <ee...@gm...> Subject: Re: [Mplapack-devel] Can I compute eigenvalues of ill-conditioned matrix less than 10^-156 ? Date: Tue, 13 Sep 2011 11:45:47 +0800 > Hi, Maho, > > > Gang, if you want to use MPACK, as Kouya-sensei wrote, please use >> GMP or MPFR version (to enlarge your precision). >> > I published a tutorial in Japanese (sorry), and >> I'll upload to the web page when I can publish my original one at the web. > > >> In the mean time, if you can use GMP version and setting >> MPACK_GMP_PRECISION environment variable to change pricision dynamically. >> > > > Yes, I used the GMP and MPFR version and tuned the precision variable from > 256 to 2048, but the results are truncated at ~10^-156. When the eigenvalues > are smaller than ~10^-156, they will become negative. How can I improve the > precision beyond 10^-156? Thanks. Hm, could you please check your inputs, so that not to include trancated values. or could you please send me your source codes. thanks Nakata Maho |