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@R) == m) # On my box I have nrow(qa@R):=207 while should be 205 as m is) Note that for m=203 and n=197, the same code produce right (i.e. coinciding) dimensions. Have I missed something? Serguei. > R.version platform x86_64-pc-linux-gnu arch x86_64 os linux-gnu system x86_64, linux-gnu status major 3 minor 4.3 year 2017 month 11 day 30 svn rev 73796 language R version.string R version 3.4.3 (2017-11-30) nickname Kite-Eating Tree ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
