Displaying 2 results from an estimated 2 matches for "powersymbol".
2008 Aug 14
3
extending the derivs table/fools rushing in
....ufl.edu/bolker/deriv_patch.txt .
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(qu...
1997 Aug 28
1
R-alpha: pow_ii
...w
[146] | 244556| 312|FUNC |LOCL |0 |7 |complex_pow
[2557] | 1462800| 0|FUNC |GLOB |0 |UNDEF |pow
[2795] | 1053360| 68|FUNC |GLOB |0 |7 |pow_dd
[2800] | 1053124| 236|FUNC |GLOB |0 |7 |pow_di
[377] | 1474036| 4|OBJT |LOCL |0 |15 |powerSymbol
[5] /R :
[5] /R : R
This leads me to wonder how R calculates powers and exp for complex
numbers. I presume that if I can arrange to call the same routines then
I can avoid the extra burden of having to include parts of libf2c with
my distributed code. Do you know what R uses and can I call these...