Oups, sorry, I missed the 'a=matrix'... 2007/7/16, Matthieu Brucher <[EMAIL PROTECTED]>:
Hi, Did you try numpy.dot(sqrtm(a), sqrtm(a)) ? Matthieu 2007/7/16, Kevin Jacobs <[EMAIL PROTECTED]> < [EMAIL PROTECTED]>: > > Hi all, > > This is a bit of a SciPy question, but I thought I'd ask here since I'm > already subscribed. I'd like to add some new LAPACK bindings to SciPy and > was wondering if there was a minimum version requirement for LAPACK, since > it would be ideal if I could use some of the newer 3.0 features. In > addition to using some block methods only added in 3.0, it is very > convenient to use the WORK=-1 for space queries instead of reimplementing > the underlying logic in the calc_work module. > > The routines of most interest to me are: > DGELSD > DGGGLM > DGGLSE > > I've also found that SciPy's sqrtm is broken: > > >>> a=matrix([[59, 64, 69], > [64, 72, 80], > [69, 80, 91]]) > >>> sqrtm(a) > array([[ 5.0084801 +1.03420519e-08j, 4.40747825 -2.06841037e-08j, > 3.8064764 +1.03420519e-08j], > [ 4.40747825 -2.06841037e-08j, 4.88353492 +4.13682075e-08j, > 5.3595916 -2.06841037e-08j], > [ 3.8064764 +1.03420519e-08j, 5.3595916 -2.06841037e-08j, > 6.9127068 +1.03420519e-08j]]) > >>> sqrtm(a)*sqrtm(a) > array([[ 25.08487289 +1.03595922e-07j, 19.42586452 -1.82329475e-07j, > 14.48926259 +7.87335527e-08j], > [ 19.42586452 -1.82329475e-07j, 23.84891336 +4.04046172e-07j, > 28.72522212 -2.21716697e-07j], > [ 14.48926259 +7.87335527e-08j, 28.72522212 -2.21716697e-07j, > 47.78551529 +1.42983144e-07j]]) > > So not even close... (and yes, it does deserve a bug report if one > doesn't already exist) > > -Kevin > > > _______________________________________________ > Numpy-discussion mailing list > [email protected] > http://projects.scipy.org/mailman/listinfo/numpy-discussion > >
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