[math] Complex Tanh for "big" numbers -------------------------------------
Key: MATH-722 URL: https://issues.apache.org/jira/browse/MATH-722 Project: Commons Math Issue Type: Bug Affects Versions: 2.2 Environment: I'm working with Eclipse 3.6.2 on Windows XP, but the bug is Enviroment independent Reporter: Juan Barandiaran Priority: Minor Hi, In Complex.java the tanh is computed with the following formula: tanh(a + bi) = sinh(2a)/(cosh(2a)+cos(2b)) + [sin(2b)/(cosh(2a)+cos(2b))]i The problem that I'm finding is that as soon as "a" is a "big" number, both sinh(2a) and cosh(2a) are infinity and then the method tanh returns in the real part NaN (infinity/infinity) when it should return 1.0. Wouldn't it be appropiate to add something as in the FastMath library??: if (real>20.0){ return createComplex(1.0, 0.0); } if (real<-20.0){ return createComplex(-1.0, 0.0); } Best regards, JBB -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira