# special library Null safety

Particular mathematical functions.

## Functions

beta(num x, num y)
Beta function based on the gamma function.
betacf_(num x, num a, num b)
Evaluates the continued fraction for incomplete beta function by modified Lentz's method.
betaLn(num x, num y)
Logarithm of the beta function based on the gammaLn function.
combination(num n, num k)
Returns the combinations based on the gamma function.
combinationLn(num n, num k)
Returns the logarithm of the combinations based on the gammaLn function.
erf(num x)
Returns an approximation of the error function, for details see https://en.wikipedia.org/wiki/Error_function.
erfc(num x)
Returns the complementary error function.
erfcInv(num x)
Returns the inverse complementary error function.
erfInv(num x)
Returns the inverse error function.
factorial(num n)
Returns the factorial based on the gamma function.
factorialLn(num n)
Returns the logarithm of the factorial based on the gammaLn function.
gamma(num x)
Returns an approximation of the gamma function, for details see https://en.wikipedia.org/wiki/Gamma_function.
gammaLn(num x)
Returns the natural logarithm of the gamma function.
gammap(num a, num x)
gammapInv(num p, num a)
ibeta(num x, num a, num b)
Incomplete beta function.
ibetaInv(num p, num a, num b)
Inverse of the incomplete beta function.
lowRegGamma(num a, num x)
permutation(num n, num m)
Returns the permutations based on the gamma function.
permutationLn(num n, num m)
Returns the logarithm of the permutations based on the gammaLn function.