double
dhyper (double x, double r, double b, double n, int give_log)
{
double p, q, p1, p2, p3;
if (isnan (x) || isnan (r) || isnan (b) || isnan (n))
return x + r + b + n;
if (R_D_negInonint (r) || R_D_negInonint (b) || R_D_negInonint (n)
|| n > r + b)
return(NAN);
if (x < 0)
return (R_D__0);
R_D_nonint_check (x); // incl warning
x = round (x);
r = round (r);
b = round (b);
n = round (n);
if (n < x || r < x || n - x > b)
return (R_D__0);
if (n == 0)
return ((x == 0) ? R_D__1 : R_D__0);
p = ((double) n) / ((double) (r + b));
q = ((double) (r + b - n)) / ((double) (r + b));
p1 = dbinom_raw (x, r, p, q, give_log);
p2 = dbinom_raw (n - x, b, p, q, give_log);
p3 = dbinom_raw (n, r + b, p, q, give_log);
return ((give_log) ? p1 + p2 - p3 : p1 * p2 / p3);
}
double dhyper(double x, double r, double b, double n, int give_log)
{
double p, q, p1, p2, p3;
#ifdef IEEE_754
if (ISNAN(x) || ISNAN(r) || ISNAN(b) || ISNAN(n))
return x + r + b + n;
#endif
if (R_D_negInonint(r) || R_D_negInonint(b) || R_D_negInonint(n) || n > r+b)
ML_ERR_return_NAN;
if (R_D_negInonint(x))
return(R_D__0);
x = R_D_forceint(x);
r = R_D_forceint(r);
b = R_D_forceint(b);
n = R_D_forceint(n);
if (n < x || r < x || n - x > b) return(R_D__0);
if (n == 0) return((x == 0) ? R_D__1 : R_D__0);
p = ((double)n)/((double)(r+b));
q = ((double)(r+b-n))/((double)(r+b));
p1 = dbinom_raw(x, r, p,q,give_log);
p2 = dbinom_raw(n-x,b, p,q,give_log);
p3 = dbinom_raw(n,r+b, p,q,give_log);
return( (give_log) ? p1 + p2 - p3 : p1*p2/p3 );
}
double dbinom(double x, double n, double p, int give_log)
{
#ifdef IEEE_754
/* NaNs propagated correctly */
if (ISNAN(x) || ISNAN(n) || ISNAN(p)) return x + n + p;
#endif
if (p < 0 || p > 1 || R_D_negInonint(n))
ML_ERR_return_NAN;
R_D_nonint_check(x);
if (x < 0 || !R_FINITE(x)) return R_D__0;
n = R_forceint(n);
x = R_forceint(x);
return dbinom_raw(x, n, p, 1-p, give_log);
}