besi0 besi0e besi1 besi1e besin besind besinu besinud besk0 besk0e besk1 besk1e beskn besknd besknu besknud cbesi cbesk sbesin sbesinu sbeskn sbesknu

besinud() double besinud ( double  nu, double  x  ) Derivative I'ν(x) of modified Bessel function of the first kind of order ν Iν(x) (fractional order) Purpose besinud computes the derivative I'ν(x) of the modified Bessel function of the first kind of order ν Iν(x). Returns 0: I'ν(x). Parameters [in] nu Order ν. [in] x Argument x. (x >= 0 if ν is not an integer) Error handling If x < 0 when nu is not an integer, domain error (EDOM) occurs. Range error (ERANGE) may occur. Reference boost/math/special_functions