Displaying 1 result from an estimated 1 matches for "plussymbol".
2008 Aug 14
3
extending the derivs table/fools rushing in
...xt .
I pretty much followed the framework of the other symbols;
here was my incantation
- } else if (CAR(expr) == PlogisSymbol) {
- ans = simplify(TimesSymbol,
- PP_S(TimesSymbol,
- PP_S2(ExpSymbol,
- PP_S2(MinusSymbol,CADR(expr))),
- PP_S(PowerSymbol,
- PP_S(PlusSymbol,
- Constant(1.),
- PP_S2(ExpSymbol,
- PP_S2(MinusSymbol,CADR(expr)))),
- Constant(-2.))),
- PP(D(CADR(expr),var)));
- UNPROTECT(8);
It seems to work:
> D(quote(plogis(a)),"a")
exp(-a) * (1 + exp(-a))^-2
> D(quote(plogis(a+b*x)),"x&q...