# MathProbabilityDensityBinomial Calculates the value of the probability mass function of binomial distribution with the n and p parameters for a random variable x. In case of error it returns [NaN](/en/docs/basis/types/double). ``` double  MathProbabilityDensityBinomial(    const double  x,             // value of random variable    const double  n,             // parameter of the distribution (number of tests)    const double  p,             // parameter of the distribution (probability of event occurrence in one test)    const bool    log_mode,      // calculate the logarithm of the value, if log_mode=true, then the natural logarithm of the probability density is calculated    int&          error_code     // variable to store the error code    ); ``` Calculates the value of the probability mass function of binomial distribution with the n and p parameters for a random variable x. In case of error it returns [NaN](/en/docs/basis/types/double). ``` double  MathProbabilityDensityBinomial(    const double  x,             // value of random variable    const double  n,             // parameter of the distribution (number of tests)    const double  p,             // parameter of the distribution (probability of event occurrence in one test)    int&          error_code     // variable to store the error code    ); ``` Calculates the value of the probability mass function of binomial distribution with the n and p parameters for an array of random variables x[]. In case of error it returns false. Analog of the [dbinom()](https://stat.ethz.ch/R-manual/R-devel/library/stats/html/Binomial.html) in R. ``` bool  MathProbabilityDensityBinomial(    const double& x[],            // array with the values of random variable    const double  n,              // parameter of the distribution (number of tests)    const double  p,              // parameter of the distribution (probability of event occurrence in one test)    const bool    log_mode,       // flag to calculate the logarithm of the value, if log_mode=true, then the natural logarithm of the probability density is calculated    double&       result[]        // array for values of the probability density function    ); ``` Calculates the value of the probability mass function of binomial distribution with the n and p parameters for an array of random variables x[]. In case of error it returns false. ``` bool  MathProbabilityDensityBinomial(    const double& x[],            // array with the values of random variable    const double  n,              // parameter of the distribution (number of tests)    const double  p,              // parameter of the distribution (probability of event occurrence in one test)    double&       result[]        // array for values of the probability density function    ); ``` Parameters x [in]  Value of random variable. x[] [in]  Array with the values of random variable. n [in]  Parameter of the distribution (number of tests). p [in]  Parameter of the distribution (probability of event occurrence in one test). log_mode [in]  Flag to calculate the logarithm of the value. If log_mode=true, then the natural logarithm of the probability density is returned. error_code [out]  Variable to store the error code. result[] [out]  Array for values of the probability density function.