[Lapackpp-devel] SVD that ignores U, Sigma or VT
Status: Beta
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From: Jacob \(Jack\) G. <jg...@cs...> - 2004-09-02 19:53:59
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Hi, I'm writing some code that only uses data from VT of an SVD, and don't need the data in U and Sigma. Although I can ignore it; the resulting U is significantly large (512^2x512^2), which is too large a matrix for the system to handle; and is clearly a waste. I've noticed that there is a function that ignores both U and VT, by essentially setting ldv and ldu to 0, that seemingly tells LAPACK to ignore the data. Maybe it would be better just to use a single LaSVD_IP function, and allow uninitialized LaGenMat[Double/Complex] as input. If, for example U is declared with the default constructor, since U.gdim(0) == 0, I would guess that LAPACK will ignore writing output to U. Any thoughts on this? Jack |