Dear all, We seem to have found a "strange" behaviour in the hyperbolic tangent function tanh on Windows. When running tanh(356 + 0i) the Windows result is NaN + 0.i while on Mac the result is 1 + 0i. It doesn't seem to be a floating point error because on Mac it is possible to run arbitrarily large numbers (say tanh( 999999677873648767519238192348124812341234182374817239847812738481234871823+0i) ) and still get 1 + 0i as result. This seems to be related to the imaginary part as tanh(356) returns 1 in both Windows and Mac.
We have obtained those results in: 1) Mac with El Capitan v 10.11.6 *processor: 2.7 GHz Intel Core i5* - 2) Mac with Sierra v 10.12.3 *processor: 3.2 GHz Intel Core i5* - 3) Windows 10 Home v 1607 *processor: Intel Core m3-SY30 CPU@ 0.90 GHz 1.51 GHz* - 4) Windows 7 Home Premium Service Pack 1 *processor: Intel Core i5-2410M CPU @2.30 GHz 2.30GHz.* In all cases we are using R version 3.3.3 (64 bits) - *Does anybody have a clue on why is this happening?* - PS: We have previously posted this issue in Stack Overflow ( http://stackoverflow.com/questions/42847414/hyperbolic-tangent-in-r-throws-nan-in-windows-but-not-in-mac). A comment suggests it is related to a glibc bug. Thanks, Rod [[alternative HTML version deleted]] ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel