## Mathematics Mathematics |

## Functions

double | acosh ()
double | asinh ()
double | atanh ()
double | expm1 ()
long double | frexpl ()
double | go_add_epsilon ()
long double | go_add_epsilonl ()
_Decimal64 | go_add_epsilonD ()
double | go_ascii_strtod ()
long double | go_ascii_strtold ()
_Decimal64 | go_ascii_strtoDd ()
double | go_atan2pi ()
long double | go_atan2pil ()
_Decimal64 | go_atan2piD ()
double | go_atanpi ()
long double | go_atanpil ()
_Decimal64 | go_atanpiD ()
void | go_continued_fraction ()
double | go_cospi ()
long double | go_cospil ()
_Decimal64 | go_cospiD ()
double | go_cotpi ()
long double | go_cotpil ()
_Decimal64 | go_cotpiD ()
void | go_dtoa ()
double | go_fake_ceil ()
long double | go_fake_ceill ()
_Decimal64 | go_fake_ceilD ()
double | go_fake_floor ()
long double | go_fake_floorl ()
_Decimal64 | go_fake_floorD ()
double | go_fake_round ()
long double | go_fake_roundl ()
_Decimal64 | go_fake_roundD ()
double | go_fake_trunc ()
long double | go_fake_truncl ()
_Decimal64 | go_fake_truncD ()
int | go_finite ()
int | go_finitel ()
int | go_finiteD ()
long double | go_log10l ()
_Decimal64 | go_log10D ()
double | go_pow ()
long double | go_powl ()
_Decimal64 | go_powD ()
double | go_pow10 ()
long double | go_pow10l ()
_Decimal64 | go_pow10D ()
double | go_pow2 ()
long double | go_pow2l ()
_Decimal64 | go_pow2D ()
double | go_rint ()
void | go_stern_brocot ()
double | go_strtod ()
long double | go_strtold ()
_Decimal64 | go_strtoDd ()
double | go_sub_epsilon ()
long double | go_sub_epsilonl ()
_Decimal64 | go_sub_epsilonD ()
long double | ldexpl ()
double | log1p ()
long double | modfl ()
long double | strtold ()

## Description

## Functions

### acosh ()

    double
    acosh (double x);

### asinh ()

    double
    asinh (double x);

### atanh ()

    double
    atanh (double x);

### expm1 ()

    double
    expm1 (double x);

### frexpl ()

    long double
    frexpl (long double x,
            int *e);

### go_add_epsilon ()

    double
    go_add_epsilon (double x);

#### Parameters

x | a number |

#### Returns

the next-larger representable value, except that zero and infinites are returned unchanged.

### go_add_epsilonl ()

    long double
    go_add_epsilonl (long double x);

#### Parameters

x | a number |

#### Returns

the next-larger representable value, except that zero and infinites are returned unchanged.

### go_add_epsilonD ()

    _Decimal64
    go_add_epsilonD (_Decimal64 x);

#### Parameters

x | a number |

#### Returns

the next-larger representable value, except that zero and infinites are returned unchanged.

### go_ascii_strtod ()

    double
    go_ascii_strtod (const char *s,
                     char **end);

Like g_ascii_strtod, but without hex notation and MS extensions. There is no need to reset errno before calling this.

#### Parameters

s | string to convert |
end | optional pointer to end of string. |

#### Returns

the converted value.

### go_ascii_strtold ()

    long double
    go_ascii_strtold (const char *s,
                      char **end);

Like strtold, but without hex notation and MS extensions and also assuming "C" locale. Unlike strtold, there is no need to reset errno before calling this.

#### Parameters

s | string to convert |
end | optional pointer to end of string. |

#### Returns

the converted value.

### go_ascii_strtoDd ()

    _Decimal64
    go_ascii_strtoDd (const char *s,
                      char **end);

Like strtoDd, but without hex notation and MS extensions and also assuming "C" locale. There is no need to reset errno before calling this.

#### Parameters

s | string to convert |
end | optional pointer to end of string. |

#### Returns

the converted value.

### go_atan2pi ()

    double
    go_atan2pi (double y,
                double x);

#### Parameters

y | a number |
x | a number |

#### Returns

the polar angle of the point (`x` ,`y` ) in radians divided by Pi. The result is a number between -1 and +1.

### go_atan2pil ()

    long double
    go_atan2pil (long double y,
                 long double x);

#### Parameters

y | a number |
x | a number |

#### Returns

the polar angle of the point (`x` ,`y` ) in radians divided by Pi. The result is a number between -1 and +1.

### go_atan2piD ()

    _Decimal64
    go_atan2piD (_Decimal64 y,
                 _Decimal64 x);

#### Parameters

y | a number |
x | a number |

#### Returns

the polar angle of the point (`x` ,`y` ) in radians divided by Pi. The result is a number between -1 and +1.

### go_atanpi ()

    double
    go_atanpi (double x);

#### Parameters

x | a number |

#### Returns

the arc tangent of `x` in radians divided by Pi. The result is a number between -1 and +1.

### go_atanpil ()

    long double
    go_atanpil (long double x);

#### Parameters

x | a number |

#### Returns

the arc tangent of `x` in radians divided by Pi. The result is a number between -1 and +1.

### go_atanpiD ()

    _Decimal64
    go_atanpiD (_Decimal64 x);

#### Parameters

x | a number |

#### Returns

the arc tangent of `x` in radians divided by Pi. The result is a number between -1 and +1.

### go_continued_fraction ()

    void
    go_continued_fraction (double val,
                           int max_denom,
                           int *res_num,
                           int *res_denom);

### go_cospi ()

    double
    go_cospi (double x);

#### Parameters

x | a number |

#### Returns

the cosine of Pi times `x` , but with less error than doing the multiplication outright.

### go_cospil ()

    long double
    go_cospil (long double x);

#### Parameters

x | a number |

#### Returns

the cosine of Pi times `x` , but with less error than doing the multiplication outright.

### go_cospiD ()

    _Decimal64
    go_cospiD (_Decimal64 x);

#### Parameters

x | a number |

#### Returns

the cosine of Pi times `x` , but with less error than doing the multiplication outright.

### go_cotpi ()

    double
    go_cotpi (double x);

#### Parameters

x | a number |

#### Returns

the cotangent of Pi times `x` , but with less error than doing the multiplication outright.

### go_cotpil ()

    long double
    go_cotpil (long double x);

#### Parameters

x | a number |

#### Returns

the cotangent of Pi times `x` , but with less error than doing the multiplication outright.

### go_cotpiD ()

    _Decimal64
    go_cotpiD (_Decimal64 x);

#### Parameters

x | a number |

#### Returns

the cotangent of Pi times `x` , but with less error than doing the multiplication outright.

### go_dtoa ()

    void
    go_dtoa (GString *dst,
             const char *fmt,
             ...);

Formats a single floating-point value. `format` should be a printf-style format fragment for a single floating-point item without the initial '%'.

If goffice has been compiled with support for type "long double", an "L" modifier can be used. If goffice has been compiled with support for type "decimal64", a "D" modifier can be used.

'*' for width and/or precision are allowed and consume an extra int argument

Certain extra flags are supported: flag '!' means to use the shortest possible representation of the number; flag '=' means to clear the `dst` before formatting (as opposed to appending); flag ',' means to format as in C locale

#### Parameters

dst | destination |
fmt | format |
... | single value to format (but see below) |

### go_fake_ceil ()

    double
    go_fake_ceil (double x);

#### Parameters

x | value to ceil |

#### Returns

the ceiling of `x` , ie., the smallest integer that is not smaller than `x` . However, this variant applies a 1 ulp grace interval for values that are just a hair larger than an integer.

### go_fake_ceill ()

    long double
    go_fake_ceill (long double x);

#### Parameters

x | value to ceil |

#### Returns

the ceiling of `x` , ie., the smallest integer that is not smaller than `x` . However, this variant applies a 1 ulp grace interval for values that are just a hair larger than an integer.

### go_fake_ceilD ()

    _Decimal64
    go_fake_ceilD (_Decimal64 x);

#### Parameters

x | value to ceil |

#### Returns

the ceiling of `x` , ie., the smallest integer that is not smaller than `x` . However, this variant applies a 1 ulp grace interval for values that are just a hair larger than an integer.

### go_fake_floor ()

    double
    go_fake_floor (double x);

#### Parameters

x | value to floor |

#### Returns

the floor of `x` , ie., the largest integer that is not larger than `x` . However, this variant applies a 1 ulp grace interval for values that are just a hair less than an integer.

### go_fake_floorl ()

    long double
    go_fake_floorl (long double x);

#### Parameters

x | value to floor |

#### Returns

the floor of `x` , ie., the largest integer that is not larger than `x` . However, this variant applies a 1 ulp grace interval for values that are just a hair less than an integer.

### go_fake_floorD ()

    _Decimal64
    go_fake_floorD (_Decimal64 x);

#### Parameters

x | value to floor |

#### Returns

the floor of `x` , ie., the largest integer that is not larger than `x` . However, this variant applies a 1 ulp grace interval for values that are just a hair less than an integer.

### go_fake_round ()

    double
    go_fake_round (double x);

#### Parameters

x | value to round |

#### Returns

`x` rounded of to nearest integer. However, this variant applies a 1 ulp grace interval for values that are just a hair less than a helf-integer.

### go_fake_roundl ()

    long double
    go_fake_roundl (long double x);

#### Parameters

x | value to round |

#### Returns

`x` rounded of to nearest integer. However, this variant applies a 1 ulp grace interval for values that are just a hair less than a helf-integer.

### go_fake_roundD ()

    _Decimal64
    go_fake_roundD (_Decimal64 x);

#### Parameters

x | value to round |

#### Returns

`x` rounded of to nearest integer. However, this variant applies a 1 ulp grace interval for values that are just a hair less than a helf-integer.

### go_fake_trunc ()

    double
    go_fake_trunc (double x);

#### Parameters

x | value to truncate |

#### Returns

`x` rounded of to nearest integer in the direction of zero. However, this variant applies a 1 ulp grace interval for values that are just a hair less than away from an integer.

### go_fake_truncl ()

    long double
    go_fake_truncl (long double x);

#### Parameters

x | value to truncate |

#### Returns

`x` rounded of to nearest integer in the direction of zero. However, this variant applies a 1 ulp grace interval for values that are just a hair less than away from an integer.

### go_fake_truncD ()

    _Decimal64
    go_fake_truncD (_Decimal64 x);

#### Parameters

x | value to truncate |

#### Returns

`x` rounded of to nearest integer in the direction of zero. However, this variant applies a 1 ulp grace interval for values that are just a hair less than away from an integer.

### go_finite ()

    int
    go_finite (double x);

### go_finitel ()

    int
    go_finitel (long double x);

### go_finiteD ()

    int
    go_finiteD (_Decimal64 x);

### go_log10l ()

    long double
    go_log10l (long double x);

### go_log10D ()

    _Decimal64
    go_log10D (_Decimal64 x);

### go_pow ()

    double
    go_pow (double x,
            double y);

Like pow, but with extra effort for `x` ==10.

#### Parameters

x | base |
y | exponent |

#### Returns

`x` ^`y` .

### go_powl ()

    long double
    go_powl (long double x,
             long double y);

Like pow, but with extra effort for `x` ==10.

#### Parameters

x | base |
y | exponent |

#### Returns

`x` ^`y` .

### go_powD ()

    _Decimal64
    go_powD (_Decimal64 x,
             _Decimal64 y);

Like pow, but with extra effort for `x` ==10.

#### Parameters

x | base |
y | exponent |

#### Returns

`x` ^`y` .

### go_pow10 ()

    double
    go_pow10 (int n);

Computes 10 to the power of `n` . This is fast and accurate (under the reasonable assumption that the compiler is accurate).

#### Parameters

n | exponent |

### go_pow10l ()

    long double
    go_pow10l (int n);

Computes 10 to the power of `n` . This is fast and accurate (under the reasonable assumption that the compiler is accurate).

#### Parameters

n | exponent |

### go_pow10D ()

    _Decimal64
    go_pow10D (int n);

Computes 10 to the power of `n` . This is fast and accurate (under the reasonable assumption that the compiler is accurate).

#### Parameters

n | exponent |

### go_pow2 ()

    double
    go_pow2 (int n);

Computes 2 to the power of `n` . This is fast and accurate.

#### Parameters

n | exponent |

### go_pow2l ()

    long double
    go_pow2l (int n);

Computes 2 to the power of `n` . This is fast and accurate.

#### Parameters

n | exponent |

### go_pow2D ()

    _Decimal64
    go_pow2D (int n);

Computes 2 to the power of `n` . This is fast and accurate.

#### Parameters

n | exponent |

### go_rint ()

    double
    go_rint (double x);

### go_stern_brocot ()

    void
    go_stern_brocot (double val,
                     int max_denom,
                     int *res_num,
                     int *res_denom);

### go_strtod ()

    double
    go_strtod (const char *s,
               char **end);

Like strtod, but without hex notation and MS extensions. Unlike strtod, there is no need to reset errno before calling this.

#### Parameters

s | string to convert |
end | pointer to end of string. | [out][transfer none][optional]

#### Returns

the numeric value of the given string.

### go_strtold ()

    long double
    go_strtold (const char *s,
                char **end);

Like strtod, but without hex notation and MS extensions. Unlike strtold, there is no need to reset errno before calling this.

#### Parameters

s | string to convert |
end | pointer to end of string. | [out][transfer none][optional]

#### Returns

the numeric value of the given string.

### go_strtoDd ()

    _Decimal64
    go_strtoDd (const char *s,
                char **end);

Like strtod, but without hex notation and MS extensions. Unlike strtod, there is no need to reset errno before calling this.

#### Parameters

s | string to convert |
end | pointer to end of string. | [out][transfer none][optional]

#### Returns

the numeric value of the given string.

### go_sub_epsilon ()

    double
    go_sub_epsilon (double x);

#### Parameters

x | a number |

#### Returns

the next-smaller representable value, except that zero and infinites are returned unchanged.

### go_sub_epsilonl ()

    long double
    go_sub_epsilonl (long double x);

#### Parameters

x | a number |

#### Returns

the next-smaller representable value, except that zero and infinites are returned unchanged.

### go_sub_epsilonD ()

    _Decimal64
    go_sub_epsilonD (_Decimal64 x);

#### Parameters

x | a number |

#### Returns

the next-smaller representable value, except that zero and infinites are returned unchanged.

### ldexpl ()

    long double
    ldexpl (long double x,
            int e);

### log1p ()

    double
    log1p (double x);

### modfl ()

    long double
    modfl (long double x,
           long double *iptr);

### strtold ()

    long double
    strtold (const char *Param1,
             char **Param2);