Mark D. Niemiec wrote: > > It is possible that a library tanh function might attempt higher > accuracy by using extended precision internally, so smaller > values of T might be necessary for them.
The tanh function in fdlibm at <http://www.netlib.org/fdlibm/s_tanh.c> calculates tanh for large arguments as tanh=:1 - 2% expm1 @: +: where expm1 is another library function calculating expm1=:_1 + ^ For arguments greater than 22, tanh is 1. I have not checked how much lower this goes. Best wishes, John ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
