Christophe TROESTLER <christophe.troest...@umons.ac.be> writes: > Package: libblas3gf > Version: 1.2.20110419-5 > Severity: important
> The routine DGEMV (with TRANS = 'N') is supposed to perform the > operation > > y ← beta * y + alpha * A * x > > where the matrix A has dimensions M×N. In particular, if N=0 (and M > > 0), A * x is the null vector (all elements are given by sums on an > empty set of indices). Consequently, if N = 0, the operation should > be > > y ← beta * y > > and NOT leave y untouched. For your convenience, I have attached a > program demonstrating the latter (wrong) behavior. I have tested the three BLAS implementations available in Debian (netlib BLAS, ATLAS and OpenBLAS), and they all give the same result (bad from your point of view). So I am not sure this is a bug. Maybe this is on purpose. If one considers this operation to be invalid (as I do), then it makes sense to do nothing. Does the documentation clearly states that BLAS supports operations on objects with one dimension equal to zero? -- .''`. Sébastien Villemot : :' : Debian Developer `. `' http://www.dynare.org/sebastien `- GPG Key: 4096R/381A7594
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