[Help-gsl] about the function " gsl_ran_gaussian ( ) "

[Yi Cao]

Hello everyone,

      I am now trying to generate some gauss random numbers (about size of
30,000).
      I found the following function in GSL, but I am not clear how to use
this function.
0. can I just call this function in my C++ code?
1. If I use cygwin to compile the C++ code containing the function, can I
just #include"gsl/gsl_randist.h" and then compile it?
2. If I use linux (SUSE), do I have to install the GSL first and then
compile the C++ code?
3.what is the first argument of the function----const gsl_rng *r ? what
value should I assign to it?

Can anyone give me some ideas?  Thanks in advance.

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double
gsl_ran_gaussian (const gsl_rng * r, const double sigma)
{
  double x, y, r2;

  do
    {
      */* choose x,y in uniform square (-1,-1) to (+1,+1) */*

      x = -1 + 2 * gsl_rng_uniform (r);
      y = -1 + 2 * gsl_rng_uniform (r);

      /* see if it is in the unit circle */
      r2 = x * x + y * y;
    }
  while (r2 > 1.0 || r2 == 0);

  */* Box-Muller transform */*
  return sigma * y * sqrt (-2.0 * log (r2) / r2);
}
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