Hi, in this example with Eigen 3.3.1

matA is equal to 1:

Eigen::Map<Eigen::MatrixXcd> matA(Az, 1, A.getLength());
Eigen::Map<Eigen::MatrixXcd> matR(Rz, 1, R.getLength());
matR = matA.array().asin();

on macos:
Darwin mac-mini.local 13.4.0 Darwin Kernel Version 13.4.0: Mon Jan 11 18:17:34 PST 2016; root:xnu-2422.115.15~1/RELEASE_X86_64 x86_64

same problem with another macos (sierra)
Darwinmy-Mac.local 16.1.0 Darwin Kernel Version 16.1.0: Thu Oct 13 21:26:57 PDT 2016; root:xnu-3789.21.3~60/RELEASE_X86_64 x86_64

imaginary part is 0.000000007825110

on windows 32 & 64 bits
imaginary part is 0.000000000000000

Bug ?

Thanks

hm, and what about std::asin(Az[1])??

ggael wrote:hm, and what about std::asin(Az[1])??

it did not return 0 ... but a value

Thanks