Sun Studio 12: Fortran Library Reference

1.3 Fortran Math Functions

The following functions and subroutines are part of the Fortran math libraries. They are available to all programs compiled with f95. These routines are non-intrinsics that take a specific data type as an argument and return the same. Non-intrinsics do have to be declared in the routine referencing them.

Many of these routines are "wrappers", Fortran interfaces to routines in the C language library, and as such are non-standard Fortran. They include IEEE recommended support functions, and specialized random number generators. See the Numerical Computation Guide and the man pages libm_single(3F), libm_double(3F), libm_quadruple(3F), for more information about these libraries.

1.3.1 Single-Precision Functions

These subprograms are single-precision math functions and subroutines.

In general, the functions below provide access to single-precision math functions that do not correspond to standard Fortran generic intrinsic functions—data types are determined by the usual data typing rules.

These functions need not be explicitly typed with a REAL statement as long as default typing holds. (Names beginning with “r” are REAL, with “i” are INTEGER.)

For details on these routines, see the C math library man pages (3M). For example, for r_acos(x) see the acos(3M) man page.

Table 1–2 Single-Precision Math Functions


Function Name	Return Type	Description
`r_acos``( x )` `r_acosd``( x )` `r_acosh``( x )` `r_acosp``( x )` `r_acospi``( x )`	`REAL` `REAL` `REAL` `REAL` `REAL`	`arc cosine` `--` `arc cosh` `--` `--`
`r_atan``( x )` `r_atand``( x )` `r_atanh``( x )` `r_atanp``( x )` `r_atanpi``( x )`	`REAL` `REAL` `REAL` `REAL` `REAL`	`arc tangent` `--` `arc tanh` `--` `--`
`r_asin``( x )` `r_asind``( x )` `r_asinh``( x )` `r_asinp``( x )` `r_asinpi``( x )`	`REAL` `REAL` `REAL` `REAL` `REAL`	`arc sine` `--` `arc sinh` `--` `--`
`r_atan2``( y, x )` `r_atan2d``( y, x )` `r_atan2pi``( y, x )`	`REAL` `REAL` `REAL`	`arc tangent` `--` `--`
`r_cbrt``( x )` `r_ceil``( x )` `r_copysign``( x, y )`	`REAL` `REAL` `REAL`	`cube root` `ceiling` `--`
`r_cos``( x )` `r_cosd``( x )` `r_cosh``( x )` `r_cosp``( x )` `r_cospi``( x )`	`REAL` `REAL` `REAL` `REAL` `REAL`	`cosine` `--` `hyperb cos` `--` `--`
`r_erf``( x )` `r_erfc``( x )`	`REAL` `REAL`	`err function` `--`
`r_expm1``( x )` `r_floor``( x )` `r_hypot``( x, y )` `r_infinity``( )`	`REAL` `REAL` `REAL` `REAL`	`(ex)-1` `floor` `hypotenuse` `--`**
`r_j0( x )` `r_j1( x )` `r_jn(n, x )`	`REAL` `REAL` `REAL`	`Bessel--` `--`
`ir_finite``( x )` `ir_fp_class``( x )` `ir_ilogb``( x )` `ir_irint``( x )` `ir_isinf``( x )` `ir_isnan``( x )` `ir_isnormal``( x )` `ir_issubnormal``( x )` `ir_iszero``( x )` `ir_signbit``( x )`	`INTEGER` `INTEGER` `INTEGER` `INTEGER` `INTEGER` `INTEGER` `INTEGER` `INTEGER` `INTEGER` `INTEGER`	`--` `--` `--` `--` `--` `--` `--` `--` `--` `--`
`r_addran``()` `r_addrans``( x, p, l, u )` `r_lcran``()` `r_lcrans``( x, p, l, u )` `r_shufrans``(x, p, l, u)`	`REAL` `subroutineREAL` `subroutine` `subroutine`	`randomnumbergenerators`
`r_lgamma( x )` `r_logb``( x )` `r_log1p``( x )` `r_log2``( x )`	`REAL` `REAL` `REAL` `REAL`	`log gamma` `--` `--` `--`
`r_max_normal``()` `r_max_subnormal``()` `r_min_normal``()` `r_min_subnormal``()` `r_nextafter``( x, y )` `r_quiet_nan``( n )` `r_remainder``( x, y )` `r_rint``( x )` `r_scalb``( x, y )` `r_scalbn``( x, n )` `r_signaling_nan``( n )` `r_significand``( x )`	`REAL` `REAL` `REAL` `REAL` `REAL` `REAL` `REAL` `REAL` `REAL` `REAL` `REAL` `REAL`
`r_sin``( x )` `r_sind``( x )` `r_sinh``( x )` `r_sinp``( x )` `r_sinpi``( x )`	`REAL` `REAL` `REAL` `REAL` `REAL`	`sine` `--` `hyperb sin` `--` `--`
`r_sincos``( x, s, c )` `r_sincosd``( x, s, c )` `r_sincosp``( x, s, c )` `r_sincospi``( x, s, c )`	`subroutine` `subroutine` `subroutine` `subroutine`	`sine & cosine` `--` `--` `--`
`r_tan``( x )` `r_tand``( x )` `r_tanh``( x )` `r_tanp``( x )` `r_tanpi``( x )`	`REAL` `REAL` `REAL` `REAL` `REAL`	`tangent` `--` `hyperb tan` `--` `--`
`r_y0( x )` `r_y1( x )` `r_yn( n, x )`	`REAL` `REAL` `REAL`	`bessel` `--` `--`

Variables c, l, p, s, u, x, and y are of type REAL. Variable n is of type INTEGER.
Type these functions as explicitly REAL if an IMPLICIT statement is in effect that types names starting with “r” to some other date type.
sind(x), asind(x), … take degrees rather than radians.

See also: intro(3M) and the Numerical Computation Guide.

1.3.2 Double-Precision Functions

The following subprograms are double-precision math functions and subroutines.

In general, these functions do not correspond to standard Fortran generic intrinsic functions—data types are determined by the usual data typing rules.

These DOUBLE PRECISION functions need to appear in a DOUBLE PRECISION statement.

Refer to the C library man pages for details: the man page for d_acos(x) is acos(3M)

Table 1–3 Double Precision Math Functions


Function Name	Return Type	Description
`d_acos``( x )` `d_acosd``( x )` `d_acosh``( x )` `d_acosp``( x )` `d_acospi``( x )`	`DOUBLE` `PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION`	`arc cosine` `--` `arc cosh` `--` `--`
`d_atan``( x )` `d_atand``( x )` `d_atanh``( x )` `d_atanp``( x )` `d_atanpi``( x )`	`DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION`	`arc tangent` `--` `arc tanh` `--` `--`
`d_asin``( x )` `d_asind``( x )` `d_asinh``( x )` `d_asinp``( x )` `d_asinpi``( x )`	`DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION`	`arc sine` `--` `arc sinh` `--` `--`
`d_atan2``( y, x )` `d_atan2d``( y, x )` `d_atan2pi``( y, x )`	`DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION`	`arc tangent` `--` `--`
`d_cbrt``( x )` `d_ceil``( x )` `d_copysign``( x, x )`	`DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION`	`cube root` `ceiling` `--`
`d_cos``( x )` `d_cosd``( x )` `d_cosh``( x )` `d_cosp``( x )` `d_cospi``( x )`	`DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION`	`cosine` `--` `hyperb cos` `--` `--`
`d_erf``( x )` `d_erfc``( x )`	`DOUBLE PRECISION` `DOUBLE PRECISION`	`error func` `--`
`d_expm1``( x )` `d_floor``( x )` `d_hypot``( x, y )` `d_infinity``( )`	`DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION`	`(ex)-1` `floor` `hypotenuse` `--`**
`d_j0( x )` `d_j1( x )` `d_jn(n, x )`	`DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION`	`Bessel` `--` `--`
`id_finite``( x )` `id_fp_class``( x )` `id_ilogb``( x )` `id_irint``( x )` `id_isinf``( x )` `id_isnan``( x )` `id_isnormal``( x )` `id_issubnormal``( x )` `id_iszero``( x )` `id_signbit``( x )`	`INTEGER` `INTEGER` `INTEGER` `INTEGER` `INTEGER` `INTEGER` `INTEGER` `INTEGER` `INTEGER` `INTEGER`
`d_addran``()` `d_addrans``(x, p, l, u)` `d_lcran``()` `d_lcrans``(x, p, l, u )` `d_shufrans``(x, p, l,u)`	`DOUBLE PRECISION` `subroutine` `DOUBLE PRECISION` `subroutine` `subroutine`	`random number generators`
`d_lgamma( x )` `d_logb``( x )` `d_log1p``( x )` `d_log2``( x )`	`DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION`	`log gamma` `--` `--` `--`
`d_max_normal``()` `d_max_subnormal``()` `d_min_normal``()` `d_min_subnormal``()` `d_nextafter``( x, y )` `d_quiet_nan``( n )` `d_remainder``( x, y )` `d_rint``( x )` `d_scalb``( x, y )` `d_scalbn``( x, n )` `d_signaling_nan``( n )` `d_significand``( x )`	`DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION`
`d_sin``( x )` `d_sind``( x )` `d_sinh``( x )` `d_sinp``( x )` `d_sinpi``( x )`	`DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION`	`sine` `--` `hyper sine` `--` `--`
`d_sincos``( x, s, c )` `d_sincosd``( x, s, c )` `d_sincosp``( x, s, c )` `d_sincospi``( x, s, c )`	`subroutine` `subroutine` `subroutine` `subroutine`	`sine & cosine` `--` `--`
`d_tan``( x )` `d_tand``( x )` `d_tanh``( x )` `d_tanp``( x )` `d_tanpi``( x )`	`DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION`	`tangent` `--` `hyperb tan` `--` `--`
`d_y0( x )` `d_y1( x )` `d_yn( n, x )`	`DOUBLE PRECISION` `DOUBLE PRECISION` `DOUBLE PRECISION`	`bessel` `--` `--`

Variables c, l, p, s, u, x, and y are of type DOUBLE PRECISION. Variable n is of type INTEGER.
Explicitly type these functions on a DOUBLE PRECISION statement or with an appropriate IMPLICIT statement).
sind(x), asind(x), … take degrees rather than radians.

See also: intro(3M) and the Numerical Computation Guide.

1.3.3 Quad-Precision Functions

These subprograms are quadruple-precision (REAL*16) math functions and subroutines.

In general, these do not correspond to standard generic intrinsic functions; data types are determined by the usual data typing rules.

The quadruple precision functions must appear in a REAL*16 statement

Table 1–4 Quadruple-Precision libm Functions


Function Name	Return Type
`q_copysign``( x, y )` `q_fabs``( x )` `q_fmod``( x )` `q_infinity``( )`	*`REAL16` `REAL16`* *`REAL16` `REAL16`*
`iq_finite``( x )` `iq_fp_class``( x )` `iq_ilogb``( x )` `iq_isinf``( x )` `iq_isnan``( x )` `iq_isnormal``( x )` `iq_issubnormal``( x )` `iq_iszero``( x )` `iq_signbit``( x )`	`INTEGER` `INTEGER` `INTEGER` `INTEGER` `INTEGER` `INTEGER` `INTEGER` `INTEGER` `INTEGER`
`q_max_normal``()` `q_max_subnormal``()` `q_min_normal``()` `q_min_subnormal``()` `q_nextafter``( x, y )` `q_quiet_nan``( n )` `q_remainder``( x, y )` `q_scalbn``( x, n )` `q_signaling_nan``( n )`	*`REAL16` `REAL16`* *`REAL16` `REAL16`* *`REAL16` `REAL16`* *`REAL16` `REAL16`* *`REAL16`**

The variables c, l, p, s, u, x, and y are of type quadruple precision. Variable n is of type INTEGER.
Explicitly type these functions with a REAL*16 statement or with an appropriate IMPLICIT statement.
sind(x), asind(x), … take degrees rather than radians.

If you need to use any other quadruple-precision libm function, you can call it using $PRAGMA C(fcn) before the call. For details, see the chapter on the C–Fortran interface in the Fortran Programming Guide.