[Rcpp-devel] not sure if it's a rcpp question or a cpp question

[Alon Honig]

I am fairly certain that this line is not kosher (and in any case it is a
confusing):

  w = pd * 0.4 / (R::pnorm((qpd - sqrt(rsq) * (-0.42) * sgtemp), 0, 1, 1,
0));

try this instead:

w = qpd - sqrt(rsq) * (-0.42) * sgtemp
w = pd * 0.4 / (R::pnorm(w, 0, 1, 1, 0));

On Wed, Mar 13, 2013 at 11:42 PM, Aileen Lin
<aileenshanhong.lin at gmail.com>wrote:

> My C code:
> //[[Rcpp::depends("Rcpp")]]
> #include <Rcpp.h>
> #include <iostream>
> using namespace Rcpp;
>
> //[[Rcpp::export]]
> NumericVector sigmutest(double pd, double rsq){
>   double qpd = R::qnorm(pd, 0, 1, 1, 0);
>   double sgtemp = 0.2;
>   double sg = 0.3;
>   double eor = 1;
>
>   double w = 0;
>   while (eor>=0.0001) {
>         sg = sgtemp;
>         w = pd * 0.4 / (R::pnorm((qpd - sqrt(rsq) * (-0.42) * sgtemp), 0,
> 1, 1, 0));
>         sgtemp = (-0.5) * w + 0.4;
>         std::cout << "sg " << sg << std::endl;
>         std::cout << "sgtemp " << sgtemp << std::endl;
>         eor = abs(sg - sgtemp);
>
>         std::cout << "error " << eor << std::endl;
>
>       }
>   NumericVector out(3);
>   out(0) = sg;
>   out(1) = sgtemp;
>   out(2) = eor;
>   return out;
> }
>
> My R code:
>
> > Rcpp::sourceCpp('src/sbi.cpp')> x <- sigmutest(0.0002327279, 0.1025499338)sg 0.2
> sgtemp 0.219135
> error 0
>
>
> Does anyone know what is going on? Thanks.
> --
> Aileen L.
>
> View my Linkedin profile: http://au.linkedin.com/in/aileen2
>
>  Being happy doesn't mean you're perfect. It just means you've decided to
> look beyond the imperfections- K.B Indiana (age 14)<http://www.boardofwisdom.com/default.asp?topic=1010&search=K%2EB+Indiana+%28age+14%29>
>
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