make check on DU4 with R-1.1.0 snapshot
Albrecht Gebhardt <albrecht.gebhardt@uni-klu.ac.at> writes:
abs(X - s$u %*% D %*% t(s$v)) - Eps
[,1] [,2] [1,] -2.109424e-15 -2.220446e-16 [2,] -1.998401e-15 -8.881784e-16 [3,] -2.220446e-15 -1.776357e-15 [4,] -1.998401e-15 -1.332268e-15 [5,] -1.998401e-15 -1.332268e-15 [6,] -1.998401e-15 4.440892e-16 [7,] -1.332268e-15 -2.220446e-15
abs(D - t(s$u) %*% X %*% s$v) - Eps
[,1] [,2] [1,] 3.108624e-15 -8.881784e-16 [2,] -1.165734e-15 -2.220446e-15 4.440892e-16 and 3.108624e-15 Eps was:
Eps
[1] 2.220446e-15
...
eps: 2.22044605E-16
So one of the calculations end up at about 5.3e-15 which is over 20 times the machine epsilon. OK, Hilbert matrices are nasty and AFAIR Alpha hardware doesn't have the extended precision of Intel FPUs but does this look reasonable enough that we should just use a bigger Eps?
O__ ---- Peter Dalgaard Blegdamsvej 3 c/ /'_ --- Dept. of Biostatistics 2200 Cph. N (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - (p.dalgaard@biostat.ku.dk) FAX: (+45) 35327907 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-devel-request@stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._