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#include "nmath.h"
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#include "nmath.h"
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double rnbinom(double size, double prob)
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double rnbinom(double size, double prob)
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{
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{
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    if(!R_FINITE(prob) || size <= 0 || prob <= 0 || prob > 1)
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    if(!R_FINITE(prob) || ISNAN(size) || size <= 0 || prob <= 0 || prob > 1)
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	/* prob = 1 is ok, PR#1218 */
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	/* prob = 1 is ok, PR#1218 */
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	ML_ERR_return_NAN;
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	ML_ERR_return_NAN;
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    if(!R_FINITE(size)) size = DBL_MAX / 2.; // '/2' to prevent rgamma() returning Inf
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    if(!R_FINITE(size)) size = DBL_MAX / 2.; // '/2' to prevent rgamma() returning Inf
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    return (prob == 1) ? 0 : rpois(rgamma(size, (1 - prob) / prob));
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    return (prob == 1) ? 0 : rpois(rgamma(size, (1 - prob) / prob));
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}
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}
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double rnbinom_mu(double size, double mu)
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double rnbinom_mu(double size, double mu)
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{
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{
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    if(!R_FINITE(mu) || size <= 0 || mu < 0)
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    if(!R_FINITE(mu) || ISNAN(size) || size <= 0 || mu < 0)
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	ML_ERR_return_NAN;
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	ML_ERR_return_NAN;
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    if(!R_FINITE(size)) size = DBL_MAX / 2.;
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    if(!R_FINITE(size)) size = DBL_MAX / 2.;
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    return (mu == 0) ? 0 : rpois(rgamma(size, mu / size));
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    return (mu == 0) ? 0 : rpois(rgamma(size, mu / size));
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}
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}