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spiney
2018 Jan 18
1
wrong matrix dimension in sparseQR
Hi,
I came across a case when the dimensions of matrices returned by qr()
operated on a sparse matrix does not coincide with the initial matrix.
Here is a spinet code that should produce an example (one of many that I could provide):
?m=205
?n=199
?set.seed(7);
?a=matrix(rnorm(m*n), m, n)
?a[sample(seq(m*n), m*(n-4))]=0
?a=as(a, "Matrix")
?qa=qr(a);
?stopifnot(nrow(qa at R) == m)
?# On my box I have nrow(qa at R):=207 while should be 205...