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Dlasq*.f can not compute the correct value

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Dlasq*.f can not compute the correct value

Postby resultant » Fri Nov 13, 2015 9:45 am

The dlasq*.f can not compute the correct value of the smallest singular value.

The test code is attached.

The dlasq1.f return 0 as the smallest singular value.
Our dqds implementation in LAPROGNC(http://www-is.amp.i.kyoto-u.ac.jp/kkimu ... ROGNC.html)
returns almost 1.0278*10^{-214} as the smallest singular value.
In addition, the bisection method for an TGK matrix in LAPACK also retuns almost 1.0278*10^{-214}.

Therefore, when you compute singular values,
please use our dqds implementation in http://www-is.amp.i.kyoto-u.ac.jp/kkimu ... ROGNC.html.

Kinji Kimura
Attachments
test.c
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resultant
 
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