> > sage: bessel_K(3,x).diff(x) >> 1/2*bessel_K(4, x) + 1/2*bessel_K(2, x) >> sage: SR(maxima_calculus(bessel_K(3,x)).diff(x)) >> -1/2*bessel_K(4, x) - 1/2*bessel_K(2, x) >> >> Given that bessel_K(3,x) is not a constant function, at least one of >> those answers must be wrong. >> > > The formula is hard-coded in sage.functions.bessel.py as > Function_Bessel_K._derivative_ (line 843). Fixing should be a one character > edit. >
I.e. return -(bessel_K(n - 1, x) + bessel_K(n + 1, x)) / Integer(2) instead of return (bessel_K(n - 1, x) + bessel_K(n + 1, x)) / Integer(2) It looks like this may have just been copied from bessel_I in the original place, most likely.. Wolfram functions also says this is a correct change, so go for it! -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
