Thomas Morley <[email protected]> writes: > 2015-10-07 13:13 GMT+02:00 David Kastrup <[email protected]>: > >> If you take a look at the following, it is quite inefficient since it >> repeats a lot of calculations instead of assigning partial results to >> let-bound variables. It also uses the straight PQ formula whereas the >> usual way to avoid numerical inaccuracies is to use the PQ formula only >> for the zero where the sign of the +/- does not lead to cancellation and >> get the other zero via Viata's rule. >> >> (define (bezier-part-min-max x1 x2 x3 x4) > [...] > > No promise, but maybe I'll take a look. > Not that I know about Viata's or L'hopital's rule, but google maybe > helpfull, otherwise I'll reask
Uh, it's Vieta's rule, sorry for the typo. L'hopital is a rule for the limit of fractions (basically, when f/g -> 0/0 you might get the limiting value by looking at the limit of the quotient of derivatives f'/g' instead). No idea how it would apply here. -- David Kastrup _______________________________________________ lilypond-user mailing list [email protected] https://lists.gnu.org/mailman/listinfo/lilypond-user
