numerical issue in contour.default?
On 13/09/2013 10:01 AM, Thomas Petzoldt wrote:
Dear R developers, I found a small issue while plotting contours of data containing both "usual" and "very small" numbers. It appeared with both R 3.0.1 and R-Devel on Windows, and I could reproduce it on Linux. Would it be possible to solve this before the upcoming release?
I don't see the error in 32 bits, but I do see it in 64 bits. I think it's really unlikely this will be fixed before 3.0.2, unless you send a well tested patch in the next few days. Code freeze is on Wednesday. Duncan Murdoch
Thanks a lot for developing this great software! Thomas Example: ######## set.seed(357) z1 <- matrix(runif(100, -1e-180, 1e-180), nrow = 10) contour(z1) # ok z2 <- matrix(c(runif(50, -1, 1), runif(50, -1e-180, 1e-180)), nrow = 10) contour(z2) # Error in contour.default(z) : k != 2 or 4 contour(z2 * 1e20) # 20 worked, 19 produced error contour(round(z2, 179)) # rounding to 179 digits works but not 180
sessionInfo()
R Under development (unstable) (2013-09-11 r63910) Platform: x86_64-w64-mingw32/x64 (64-bit) locale: [1] LC_COLLATE=German_Germany.1252 LC_CTYPE=German_Germany.1252 [3] LC_MONETARY=German_Germany.1252 LC_NUMERIC=C [5] LC_TIME=German_Germany.1252 attached base packages: [1] stats graphics grDevices utils datasets methods base