Special Functions

The Intel Math library supports the following special functions:

ANNUITY

Description: The annuity function computes the present value factor for an annuity, (1-(1+x)^-y)/x, where x is a rate and y is a period.

Calling interface:

double annuity(double x, double y);
float annuityf(float x, double y);

/* All annuity functions: IA-32 only */

COMPOUND

Description: The compound function computes the compound interest factor, (1+x)^y, where x is a rate and y is a period.

Calling interface:

double compound(double x, double y);
float compoundf(float x, double y);

/* All compound functions: IA-32 only */

ERF

Description: The erf function returns the error function value.

Calling interface:

long double erfl(long double x);
double erf(double x);
float erff(float x);

ERFC

Description: The erfc function returns the complementary error function value.

Calling interface:

long double erfcl(long double x);
double erfc(double x);
float erfcf(float x);

GAMMA

Description: The gamma function returns the value of the logarithm of the absolute value of gamma.

Calling interface:

double gamma(double x);
float gammaf(float x);

GAMMA_R

Description: The gamma_r function returns the value of the logarithm of the absolute value of gamma. The sign of the gamma func­tion is returned in the external integer signgam.

Calling interface:

double gamma_r(double x, int *signgam);
float gammaf_r(float x, int *signgam);

J0

Description: Computes the Bessel function (of the first kind) of x with order 0.

Calling interface:

double j0(double x);
float j0f(float x);

J1

Description: Computes the Bessel function (of the first kind) of x with order 1.

Calling interface:

double j1(double x);
float j1f(float x);

JN

Description: Computes the Bessel function (of the first kind) of x with order n.

Calling interface:

double jn(int n, double x);
float jnf(int n, float x);

LGAMMA

Description: The lgamma function returns the value of the logarithm of the absolute value of gamma.

Calling interface:

long double lgammal(long double x); /* Itanium®-based systems only */
double lgamma(double x);
float lgammaf(float x);

LGAMMA_R

Description: The lgamma_r function returns the value of the logarithm of the absolute value of gamma. The sign of the gamma func­tion is returned in the external integer signgam.

Calling interface:

double lgamma_r(double x, int *signgam);
float lgammaf_r(float x, int *signgam);

TGAMMA

Description: The tgamma function computes the gamma function of x.

Calling interface:

long double tgammal(long double x); /* Itanium-based systems only */
double tgamma(double x);
float tgammaf(float x);

Y0

Description: Computes the Bessel function (of the second kind) of x with order 0.

Calling interface:

double y0(double x);
float y0f(float x);

Y1

Description: Computes the Bessel function (of the second kind) of x with order 1.

Calling interface:

double y1(double x);
float y1f(float x);

YN

Description: Computes the Bessel function (of the second kind) of x with order n.

Calling interface:

double yn(int n, double x);
float ynf(int n, float x);