I don't know the answer to your question, but its probably more helpful to take a look at the SVD algorithm description in Golub and Van Loan, on which the GSL code is probably based. Also its probably worthwhile to look at the original paper, which I found here:
http://people.duke.edu/~hpgavin/SystemID/References/Golub+Reinsch-NM-1970.pdf There is a complete pseudo-code writeup given in section 4. Patrick On 06/16/2017 04:19 PM, Marco Ippolito wrote: > Hi all > I do not undderstand this while cycle : > https://github.com/ampl/gsl/blob/master/linalg/svd.c#L117 > > It seems to me that the only time when b is decremented is here: > https://github.com/ampl/gsl/blob/master/linalg/svd.c#L123 > so when fbm1 == 0.0 where fb1 is the value of f at index = b-1 : > https://github.com/ampl/gsl/blob/master/linalg/svd.c#L119 > > Since I'm trying to write my own C++11 code based on GSL code, I would like > to understand how it can work. > Any ideas? > > Looking forward to your kind help. > Marco
