I wish I knew! So I asked Google. Here's what I learned:
Most implementations are based on, or similar to the implementation in the fdlibm package. sinh(x) and cosh(x) are both based on exp(x). See http:// www.netlib.org/cgi-bin/netlibfiles.pl?filename=/fdlibm/e_sinh.c exp(x) is implemented by: 1. reducing x into the range |r| <= 0.5 * ln(2), such that x = k * ln(2) + r 2. approximating exp(r) with a fifth-order polynomial, 3. re-scaling by multiplying by 2^k: exp(x) = 2^k * exp(r) sinh(x) is mathematically ( exp(x) - exp(-x) )/2 but it's not calculated directly that way. My brain hurts at this point; it's late. I'll have another go at hunting down the errors tomorrow. In the interim, does anybody out there already know the answer? :--David On Mar 4, 2006, at 8:27 PM, sam wrote: > David I beg I beg > Can you answer the question? > > Also thanks for the information on using the Taylor series. > > Sam Schulenburg > > -- > http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list