d_rndzsmail.c
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	#include<math.h>
	#include<fonction.h>

	/* -------------------------------------------------------------------
	generate a redshift for a source following a Smail et al. distribution
	------------------------------------------------------------------*/

	// Sampling of the Smail et al. function. Make sure this number is significantly larger
	// than your sample of objects for which you want to get a redshift, so
	// that each return redshift is unique
	#define KSMAIL 1000

	// Return a pointer to a structure that help speedup the following calculations
	// (see gsl: General-Discrete-Distributions.html)
	gsl_ran_discrete_t* smailpreproc()
	{
	extern struct g_source S;
	int i;
	double z, p[KSMAIL];

	// Compute the Smail et al. array in [zsmin, zsmax]
	for( i = 0; i < KSMAIL; i++ )
	{
	z = S.zsmin + i * (S.zsmax - S.zsmin) / (KSMAIL-1);
	p[i] = pow(z, S.par1) * exp(-pow(z/S.par2, S.par3));
	}

	return gsl_ran_discrete_preproc(KSMAIL, p);
	}

	/* Return a redshift validating the Smail et al. function defined with parameters
	* in g_source structure.
	* Input :
	* - r : random seed
	* - g : gsl structure obtained from smailpreproc()
	*/
	double d_rndzsmail(gsl_rng * r, gsl_ran_discrete_t * g)
	{
	extern struct g_source S;
	size_t i;
	double zrnd;

	i = gsl_ran_discrete (r, g);
	zrnd = S.zsmin + i * (S.zsmax - S.zsmin) / (KSMAIL - 1);

	return zrnd;
	}