jerry.lewis at biogenidec.com
2009-Oct-23 03:55 UTC
[Rd] (PR#14020) trigamma for very large arguments
More generally, the accuracy and working range of psigamma(x,deriv) can be improved by having it return the leading term of the asymptotic expansion (-1)^(deriv-1)*factorial(deriv-1)/x^deriv whenever deriv>=1 and x>=1e15 [[alternative HTML version deleted]]