I expect Kip knows all that, but is interested in exactly what he said, tacitly computing a function by a series.
I have an example of doing what you said, which is deciding how many terms are needed and then only computing those terms. See: http://www.jsoftware.com/jwiki/Essays/Extended_Precision_Functions#Exponential Other functions on the page also do the same. The idea is to compute various functions to any specified but finite precision using rational numbers. A direct computation on rationals does not terminate, of course, so the approach of computing the number of required terms is needed. On Sun, Dec 22, 2013 at 2:48 AM, Bo Jacoby <[email protected]> wrote: > Don't be interested in terminating a series when its partial sums stop > changing. If the partial sums never stop changing, then the program cycles, > which you don't want. Make up your mind how many terms you want to include > in the worst case, and then use that number of terms in any case. That > leads to simpler programming and fewer programming errors. Noone cares > about a little waste of cpu-time. > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
