# Primitive Type f32 [−]

The 32-bit floating point type.

See also the `std::f32` module.

## Methods

### `impl f32`
[src]

#### `fn is_nan(self) -> bool`
1.0.0

Returns `true` if this value is `NaN` and false otherwise.

fn main() { use std::f32; let nan = f32::NAN; let f = 7.0_f32; assert!(nan.is_nan()); assert!(!f.is_nan()); }

    use std::f32;

    let nan = f32::NAN;
    let f = 7.0_f32;

    assert!(nan.is_nan());
    assert!(!f.is_nan());

#### `fn is_infinite(self) -> bool`
1.0.0

Returns `true` if this value is positive infinity or negative infinity and false otherwise.

fn main() { use std::f32; let f = 7.0f32; let inf = f32::INFINITY; let neg_inf = f32::NEG_INFINITY; let nan = f32::NAN; assert!(!f.is_infinite()); assert!(!nan.is_infinite()); assert!(inf.is_infinite()); assert!(neg_inf.is_infinite()); }

    use std::f32;

    let f = 7.0f32;
    let inf = f32::INFINITY;
    let neg_inf = f32::NEG_INFINITY;
    let nan = f32::NAN;

    assert!(!f.is_infinite());
    assert!(!nan.is_infinite());

    assert!(inf.is_infinite());
    assert!(neg_inf.is_infinite());

#### `fn is_finite(self) -> bool`
1.0.0

Returns `true` if this number is neither infinite nor `NaN`.

fn main() { use std::f32; let f = 7.0f32; let inf = f32::INFINITY; let neg_inf = f32::NEG_INFINITY; let nan = f32::NAN; assert!(f.is_finite()); assert!(!nan.is_finite()); assert!(!inf.is_finite()); assert!(!neg_inf.is_finite()); }

    use std::f32;

    let f = 7.0f32;
    let inf = f32::INFINITY;
    let neg_inf = f32::NEG_INFINITY;
    let nan = f32::NAN;

    assert!(f.is_finite());

    assert!(!nan.is_finite());
    assert!(!inf.is_finite());
    assert!(!neg_inf.is_finite());

#### `fn is_normal(self) -> bool`
1.0.0

Returns `true` if the number is neither zero, infinite, subnormal, or `NaN`.

fn main() { use std::f32; let min = f32::MIN_POSITIVE; // 1.17549435e-38f32 let max = f32::MAX; let lower_than_min = 1.0e-40_f32; let zero = 0.0_f32; assert!(min.is_normal()); assert!(max.is_normal()); assert!(!zero.is_normal()); assert!(!f32::NAN.is_normal()); assert!(!f32::INFINITY.is_normal()); // Values between `0` and `min` are Subnormal. assert!(!lower_than_min.is_normal()); }

    use std::f32;

    let min = f32::MIN_POSITIVE; // 1.17549435e-38f32
    let max = f32::MAX;
    let lower_than_min = 1.0e-40_f32;
    let zero = 0.0_f32;

    assert!(min.is_normal());
    assert!(max.is_normal());

    assert!(!zero.is_normal());
    assert!(!f32::NAN.is_normal());
    assert!(!f32::INFINITY.is_normal());
    // Values between `0` and `min` are Subnormal.
    assert!(!lower_than_min.is_normal());

#### `fn classify(self) -> FpCategory`
1.0.0

Returns the floating point category of the number. If only one property is going to be tested, it is generally faster to use the specific predicate instead.

fn main() { use std::num::FpCategory; use std::f32; let num = 12.4_f32; let inf = f32::INFINITY; assert_eq!(num.classify(), FpCategory::Normal); assert_eq!(inf.classify(), FpCategory::Infinite); }

    use std::num::FpCategory;
    use std::f32;

    let num = 12.4_f32;
    let inf = f32::INFINITY;

    assert_eq!(num.classify(), FpCategory::Normal);
    assert_eq!(inf.classify(), FpCategory::Infinite);

#### `fn integer_decode(self) -> (u64, i16, i8)`

Deprecated since 1.11.0

: never really came to fruition and easily implementable outside the standard library

Unstable (`float_extras` #27752)

: never really came to fruition and easily implementable outside the standard library

Returns the mantissa, base 2 exponent, and sign as integers, respectively. The original number can be recovered by `sign * mantissa * 2 ^ exponent`. The floating point encoding is documented in the Reference.

#![feature(float_extras)] fn main() { use std::f32; let num = 2.0f32; // (8388608, -22, 1) let (mantissa, exponent, sign) = num.integer_decode(); let sign_f = sign as f32; let mantissa_f = mantissa as f32; let exponent_f = num.powf(exponent as f32); // 1 * 8388608 * 2^(-22) == 2 let abs_difference = (sign_f * mantissa_f * exponent_f - num).abs(); assert!(abs_difference <= f32::EPSILON); }

    #![feature(float_extras)]

    use std::f32;

    let num = 2.0f32;

    // (8388608, -22, 1)
    let (mantissa, exponent, sign) = num.integer_decode();
    let sign_f = sign as f32;
    let mantissa_f = mantissa as f32;
    let exponent_f = num.powf(exponent as f32);

    // 1 * 8388608 * 2^(-22) == 2
    let abs_difference = (sign_f * mantissa_f * exponent_f - num).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn floor(self) -> f32`
1.0.0

Returns the largest integer less than or equal to a number.

fn main() { let f = 3.99_f32; let g = 3.0_f32; assert_eq!(f.floor(), 3.0); assert_eq!(g.floor(), 3.0); }

    let f = 3.99_f32;
    let g = 3.0_f32;

    assert_eq!(f.floor(), 3.0);
    assert_eq!(g.floor(), 3.0);

#### `fn ceil(self) -> f32`
1.0.0

Returns the smallest integer greater than or equal to a number.

fn main() { let f = 3.01_f32; let g = 4.0_f32; assert_eq!(f.ceil(), 4.0); assert_eq!(g.ceil(), 4.0); }

    let f = 3.01_f32;
    let g = 4.0_f32;

    assert_eq!(f.ceil(), 4.0);
    assert_eq!(g.ceil(), 4.0);

#### `fn round(self) -> f32`
1.0.0

Returns the nearest integer to a number. Round half-way cases away from `0.0`.

fn main() { let f = 3.3_f32; let g = -3.3_f32; assert_eq!(f.round(), 3.0); assert_eq!(g.round(), -3.0); }

    let f = 3.3_f32;
    let g = -3.3_f32;

    assert_eq!(f.round(), 3.0);
    assert_eq!(g.round(), -3.0);

#### `fn trunc(self) -> f32`
1.0.0

Returns the integer part of a number.

fn main() { let f = 3.3_f32; let g = -3.7_f32; assert_eq!(f.trunc(), 3.0); assert_eq!(g.trunc(), -3.0); }

    let f = 3.3_f32;
    let g = -3.7_f32;

    assert_eq!(f.trunc(), 3.0);
    assert_eq!(g.trunc(), -3.0);

#### `fn fract(self) -> f32`
1.0.0

Returns the fractional part of a number.

fn main() { use std::f32; let x = 3.5_f32; let y = -3.5_f32; let abs_difference_x = (x.fract() - 0.5).abs(); let abs_difference_y = (y.fract() - (-0.5)).abs(); assert!(abs_difference_x <= f32::EPSILON); assert!(abs_difference_y <= f32::EPSILON); }

    use std::f32;

    let x = 3.5_f32;
    let y = -3.5_f32;
    let abs_difference_x = (x.fract() - 0.5).abs();
    let abs_difference_y = (y.fract() - (-0.5)).abs();

    assert!(abs_difference_x <= f32::EPSILON);
    assert!(abs_difference_y <= f32::EPSILON);

#### `fn abs(self) -> f32`
1.0.0

Computes the absolute value of `self`. Returns `NAN` if the number is `NAN`.

fn main() { use std::f32; let x = 3.5_f32; let y = -3.5_f32; let abs_difference_x = (x.abs() - x).abs(); let abs_difference_y = (y.abs() - (-y)).abs(); assert!(abs_difference_x <= f32::EPSILON); assert!(abs_difference_y <= f32::EPSILON); assert!(f32::NAN.abs().is_nan()); }

    use std::f32;

    let x = 3.5_f32;
    let y = -3.5_f32;

    let abs_difference_x = (x.abs() - x).abs();
    let abs_difference_y = (y.abs() - (-y)).abs();

    assert!(abs_difference_x <= f32::EPSILON);
    assert!(abs_difference_y <= f32::EPSILON);

    assert!(f32::NAN.abs().is_nan());

#### `fn signum(self) -> f32`
1.0.0

Returns a number that represents the sign of `self`.

- `1.0` if the number is positive, `+0.0` or `INFINITY`
- `-1.0` if the number is negative, `-0.0` or `NEG_INFINITY`
- `NAN` if the number is `NAN`

fn main() { use std::f32; let f = 3.5_f32; assert_eq!(f.signum(), 1.0); assert_eq!(f32::NEG_INFINITY.signum(), -1.0); assert!(f32::NAN.signum().is_nan()); }

    use std::f32;

    let f = 3.5_f32;

    assert_eq!(f.signum(), 1.0);
    assert_eq!(f32::NEG_INFINITY.signum(), -1.0);

    assert!(f32::NAN.signum().is_nan());

#### `fn is_sign_positive(self) -> bool`
1.0.0

Returns `true` if `self`'s sign bit is positive, including `+0.0` and `INFINITY`.

fn main() { use std::f32; let nan = f32::NAN; let f = 7.0_f32; let g = -7.0_f32; assert!(f.is_sign_positive()); assert!(!g.is_sign_positive()); // Requires both tests to determine if is `NaN` assert!(!nan.is_sign_positive() && !nan.is_sign_negative()); }

    use std::f32;

    let nan = f32::NAN;
    let f = 7.0_f32;
    let g = -7.0_f32;

    assert!(f.is_sign_positive());
    assert!(!g.is_sign_positive());
    // Requires both tests to determine if is `NaN`
    assert!(!nan.is_sign_positive() && !nan.is_sign_negative());

#### `fn is_sign_negative(self) -> bool`
1.0.0

Returns `true` if `self`'s sign is negative, including `-0.0` and `NEG_INFINITY`.

fn main() { use std::f32; let nan = f32::NAN; let f = 7.0f32; let g = -7.0f32; assert!(!f.is_sign_negative()); assert!(g.is_sign_negative()); // Requires both tests to determine if is `NaN`. assert!(!nan.is_sign_positive() && !nan.is_sign_negative()); }

    use std::f32;

    let nan = f32::NAN;
    let f = 7.0f32;
    let g = -7.0f32;

    assert!(!f.is_sign_negative());
    assert!(g.is_sign_negative());
    // Requires both tests to determine if is `NaN`.
    assert!(!nan.is_sign_positive() && !nan.is_sign_negative());

#### `fn mul_add(self, a: f32, b: f32) -> f32`
1.0.0

Fused multiply-add. Computes `(self * a) + b` with only one rounding error. This produces a more accurate result with better performance than a separate multiplication operation followed by an add.

fn main() { use std::f32; let m = 10.0_f32; let x = 4.0_f32; let b = 60.0_f32; // 100.0 let abs_difference = (m.mul_add(x, b) - (m*x + b)).abs(); assert!(abs_difference <= f32::EPSILON); }

    use std::f32;

    let m = 10.0_f32;
    let x = 4.0_f32;
    let b = 60.0_f32;

    // 100.0
    let abs_difference = (m.mul_add(x, b) - (m*x + b)).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn recip(self) -> f32`
1.0.0

Takes the reciprocal (inverse) of a number, `1/x`.

fn main() { use std::f32; let x = 2.0_f32; let abs_difference = (x.recip() - (1.0/x)).abs(); assert!(abs_difference <= f32::EPSILON); }

    use std::f32;

    let x = 2.0_f32;
    let abs_difference = (x.recip() - (1.0/x)).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn powi(self, n: i32) -> f32`
1.0.0

Raises a number to an integer power.

Using this function is generally faster than using `powf`

fn main() { use std::f32; let x = 2.0_f32; let abs_difference = (x.powi(2) - x*x).abs(); assert!(abs_difference <= f32::EPSILON); }

    use std::f32;

    let x = 2.0_f32;
    let abs_difference = (x.powi(2) - x*x).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn powf(self, n: f32) -> f32`
1.0.0

Raises a number to a floating point power.

fn main() { use std::f32; let x = 2.0_f32; let abs_difference = (x.powf(2.0) - x*x).abs(); assert!(abs_difference <= f32::EPSILON); }

    use std::f32;

    let x = 2.0_f32;
    let abs_difference = (x.powf(2.0) - x*x).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn sqrt(self) -> f32`
1.0.0

Takes the square root of a number.

Returns NaN if `self` is a negative number.

fn main() { use std::f32; let positive = 4.0_f32; let negative = -4.0_f32; let abs_difference = (positive.sqrt() - 2.0).abs(); assert!(abs_difference <= f32::EPSILON); assert!(negative.sqrt().is_nan()); }

    use std::f32;

    let positive = 4.0_f32;
    let negative = -4.0_f32;

    let abs_difference = (positive.sqrt() - 2.0).abs();

    assert!(abs_difference <= f32::EPSILON);
    assert!(negative.sqrt().is_nan());

#### `fn exp(self) -> f32`
1.0.0

Returns `e^(self)`, (the exponential function).

fn main() { use std::f32; let one = 1.0f32; // e^1 let e = one.exp(); // ln(e) - 1 == 0 let abs_difference = (e.ln() - 1.0).abs(); assert!(abs_difference <= f32::EPSILON); }

    use std::f32;

    let one = 1.0f32;
    // e^1
    let e = one.exp();

    // ln(e) - 1 == 0
    let abs_difference = (e.ln() - 1.0).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn exp2(self) -> f32`
1.0.0

Returns `2^(self)`.

fn main() { use std::f32; let f = 2.0f32; // 2^2 - 4 == 0 let abs_difference = (f.exp2() - 4.0).abs(); assert!(abs_difference <= f32::EPSILON); }

    use std::f32;

    let f = 2.0f32;

    // 2^2 - 4 == 0
    let abs_difference = (f.exp2() - 4.0).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn ln(self) -> f32`
1.0.0

Returns the natural logarithm of the number.

fn main() { use std::f32; let one = 1.0f32; // e^1 let e = one.exp(); // ln(e) - 1 == 0 let abs_difference = (e.ln() - 1.0).abs(); assert!(abs_difference <= f32::EPSILON); }

    use std::f32;

    let one = 1.0f32;
    // e^1
    let e = one.exp();

    // ln(e) - 1 == 0
    let abs_difference = (e.ln() - 1.0).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn log(self, base: f32) -> f32`
1.0.0

Returns the logarithm of the number with respect to an arbitrary base.

fn main() { use std::f32; let ten = 10.0f32; let two = 2.0f32; // log10(10) - 1 == 0 let abs_difference_10 = (ten.log(10.0) - 1.0).abs(); // log2(2) - 1 == 0 let abs_difference_2 = (two.log(2.0) - 1.0).abs(); assert!(abs_difference_10 <= f32::EPSILON); assert!(abs_difference_2 <= f32::EPSILON); }

    use std::f32;

    let ten = 10.0f32;
    let two = 2.0f32;

    // log10(10) - 1 == 0
    let abs_difference_10 = (ten.log(10.0) - 1.0).abs();

    // log2(2) - 1 == 0
    let abs_difference_2 = (two.log(2.0) - 1.0).abs();

    assert!(abs_difference_10 <= f32::EPSILON);
    assert!(abs_difference_2 <= f32::EPSILON);

#### `fn log2(self) -> f32`
1.0.0

Returns the base 2 logarithm of the number.

fn main() { use std::f32; let two = 2.0f32; // log2(2) - 1 == 0 let abs_difference = (two.log2() - 1.0).abs(); assert!(abs_difference <= f32::EPSILON); }

    use std::f32;

    let two = 2.0f32;

    // log2(2) - 1 == 0
    let abs_difference = (two.log2() - 1.0).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn log10(self) -> f32`
1.0.0

Returns the base 10 logarithm of the number.

fn main() { use std::f32; let ten = 10.0f32; // log10(10) - 1 == 0 let abs_difference = (ten.log10() - 1.0).abs(); assert!(abs_difference <= f32::EPSILON); }

    use std::f32;

    let ten = 10.0f32;

    // log10(10) - 1 == 0
    let abs_difference = (ten.log10() - 1.0).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn to_degrees(self) -> f32`
1.7.0

Converts radians to degrees.

fn main() { use std::f32::{self, consts}; let angle = consts::PI; let abs_difference = (angle.to_degrees() - 180.0).abs(); assert!(abs_difference <= f32::EPSILON); }

    use std::f32::{self, consts};

    let angle = consts::PI;

    let abs_difference = (angle.to_degrees() - 180.0).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn to_radians(self) -> f32`
1.7.0

Converts degrees to radians.

fn main() { use std::f32::{self, consts}; let angle = 180.0f32; let abs_difference = (angle.to_radians() - consts::PI).abs(); assert!(abs_difference <= f32::EPSILON); }

    use std::f32::{self, consts};

    let angle = 180.0f32;

    let abs_difference = (angle.to_radians() - consts::PI).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn ldexp(x: f32, exp: isize) -> f32`

Deprecated since 1.11.0

: never really came to fruition and easily implementable outside the standard library

Unstable (`float_extras` #27752)

: never really came to fruition and easily implementable outside the standard library

Constructs a floating point number of `x*2^exp`.

#![feature(float_extras)] fn main() { use std::f32; // 3*2^2 - 12 == 0 let abs_difference = (f32::ldexp(3.0, 2) - 12.0).abs(); assert!(abs_difference <= f32::EPSILON); }

    #![feature(float_extras)]

    use std::f32;
    // 3*2^2 - 12 == 0
    let abs_difference = (f32::ldexp(3.0, 2) - 12.0).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn frexp(self) -> (f32, isize)`

Deprecated since 1.11.0

: never really came to fruition and easily implementable outside the standard library

Unstable (`float_extras` #27752)

: never really came to fruition and easily implementable outside the standard library

Breaks the number into a normalized fraction and a base-2 exponent, satisfying:

- `self = x * 2^exp`
- `0.5 <= abs(x) < 1.0`

#![feature(float_extras)] fn main() { use std::f32; let x = 4.0f32; // (1/2)*2^3 -> 1 * 8/2 -> 4.0 let f = x.frexp(); let abs_difference_0 = (f.0 - 0.5).abs(); let abs_difference_1 = (f.1 as f32 - 3.0).abs(); assert!(abs_difference_0 <= f32::EPSILON); assert!(abs_difference_1 <= f32::EPSILON); }

    #![feature(float_extras)]

    use std::f32;

    let x = 4.0f32;

    // (1/2)*2^3 -> 1 * 8/2 -> 4.0
    let f = x.frexp();
    let abs_difference_0 = (f.0 - 0.5).abs();
    let abs_difference_1 = (f.1 as f32 - 3.0).abs();

    assert!(abs_difference_0 <= f32::EPSILON);
    assert!(abs_difference_1 <= f32::EPSILON);

#### `fn next_after(self, other: f32) -> f32`

Deprecated since 1.11.0

: never really came to fruition and easily implementable outside the standard library

Unstable (`float_extras` #27752)

: never really came to fruition and easily implementable outside the standard library

Returns the next representable floating-point value in the direction of `other`.

#![feature(float_extras)] fn main() { use std::f32; let x = 1.0f32; let abs_diff = (x.next_after(2.0) - 1.00000011920928955078125_f32).abs(); assert!(abs_diff <= f32::EPSILON); }

    #![feature(float_extras)]

    use std::f32;

    let x = 1.0f32;

    let abs_diff = (x.next_after(2.0) - 1.00000011920928955078125_f32).abs();

    assert!(abs_diff <= f32::EPSILON);

#### `fn max(self, other: f32) -> f32`
1.0.0

Returns the maximum of the two numbers.

fn main() { let x = 1.0f32; let y = 2.0f32; assert_eq!(x.max(y), y); }

    let x = 1.0f32;
    let y = 2.0f32;

    assert_eq!(x.max(y), y);

If one of the arguments is NaN, then the other argument is returned.

#### `fn min(self, other: f32) -> f32`
1.0.0

Returns the minimum of the two numbers.

fn main() { let x = 1.0f32; let y = 2.0f32; assert_eq!(x.min(y), x); }

    let x = 1.0f32;
    let y = 2.0f32;

    assert_eq!(x.min(y), x);

If one of the arguments is NaN, then the other argument is returned.

#### `fn abs_sub(self, other: f32) -> f32`
1.0.0

Deprecated since 1.10.0

: you probably meant `(self - other).abs()`: this operation is `(self - other).max(0.0)` (also known as `fdimf` in C). If you truly need the positive difference, consider using that expression or the C function `fdimf`, depending on how you wish to handle NaN (please consider filing an issue describing your use-case too).

The positive difference of two numbers.

- If `self <= other`: `0:0`
- Else: `self - other`

fn main() { use std::f32; let x = 3.0f32; let y = -3.0f32; let abs_difference_x = (x.abs_sub(1.0) - 2.0).abs(); let abs_difference_y = (y.abs_sub(1.0) - 0.0).abs(); assert!(abs_difference_x <= f32::EPSILON); assert!(abs_difference_y <= f32::EPSILON); }

    use std::f32;

    let x = 3.0f32;
    let y = -3.0f32;

    let abs_difference_x = (x.abs_sub(1.0) - 2.0).abs();
    let abs_difference_y = (y.abs_sub(1.0) - 0.0).abs();

    assert!(abs_difference_x <= f32::EPSILON);
    assert!(abs_difference_y <= f32::EPSILON);

#### `fn cbrt(self) -> f32`
1.0.0

Takes the cubic root of a number.

fn main() { use std::f32; let x = 8.0f32; // x^(1/3) - 2 == 0 let abs_difference = (x.cbrt() - 2.0).abs(); assert!(abs_difference <= f32::EPSILON); }

    use std::f32;

    let x = 8.0f32;

    // x^(1/3) - 2 == 0
    let abs_difference = (x.cbrt() - 2.0).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn hypot(self, other: f32) -> f32`
1.0.0

Calculates the length of the hypotenuse of a right-angle triangle given legs of length `x` and `y`.

fn main() { use std::f32; let x = 2.0f32; let y = 3.0f32; // sqrt(x^2 + y^2) let abs_difference = (x.hypot(y) - (x.powi(2) + y.powi(2)).sqrt()).abs(); assert!(abs_difference <= f32::EPSILON); }

    use std::f32;

    let x = 2.0f32;
    let y = 3.0f32;

    // sqrt(x^2 + y^2)
    let abs_difference = (x.hypot(y) - (x.powi(2) + y.powi(2)).sqrt()).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn sin(self) -> f32`
1.0.0

Computes the sine of a number (in radians).

fn main() { use std::f32; let x = f32::consts::PI/2.0; let abs_difference = (x.sin() - 1.0).abs(); assert!(abs_difference <= f32::EPSILON); }

    use std::f32;

    let x = f32::consts::PI/2.0;

    let abs_difference = (x.sin() - 1.0).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn cos(self) -> f32`
1.0.0

Computes the cosine of a number (in radians).

fn main() { use std::f32; let x = 2.0*f32::consts::PI; let abs_difference = (x.cos() - 1.0).abs(); assert!(abs_difference <= f32::EPSILON); }

    use std::f32;

    let x = 2.0*f32::consts::PI;

    let abs_difference = (x.cos() - 1.0).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn tan(self) -> f32`
1.0.0

Computes the tangent of a number (in radians).

fn main() { use std::f32; let x = f32::consts::PI / 4.0; let abs_difference = (x.tan() - 1.0).abs(); assert!(abs_difference <= f32::EPSILON); }

    use std::f32;

    let x = f32::consts::PI / 4.0;
    let abs_difference = (x.tan() - 1.0).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn asin(self) -> f32`
1.0.0

Computes the arcsine of a number. Return value is in radians in the range [-pi/2, pi/2] or NaN if the number is outside the range [-1, 1].

fn main() { use std::f32; let f = f32::consts::PI / 2.0; // asin(sin(pi/2)) let abs_difference = (f.sin().asin() - f32::consts::PI / 2.0).abs(); assert!(abs_difference <= f32::EPSILON); }

    use std::f32;

    let f = f32::consts::PI / 2.0;

    // asin(sin(pi/2))
    let abs_difference = (f.sin().asin() - f32::consts::PI / 2.0).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn acos(self) -> f32`
1.0.0

Computes the arccosine of a number. Return value is in radians in the range [0, pi] or NaN if the number is outside the range [-1, 1].

fn main() { use std::f32; let f = f32::consts::PI / 4.0; // acos(cos(pi/4)) let abs_difference = (f.cos().acos() - f32::consts::PI / 4.0).abs(); assert!(abs_difference <= f32::EPSILON); }

    use std::f32;

    let f = f32::consts::PI / 4.0;

    // acos(cos(pi/4))
    let abs_difference = (f.cos().acos() - f32::consts::PI / 4.0).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn atan(self) -> f32`
1.0.0

Computes the arctangent of a number. Return value is in radians in the range [-pi/2, pi/2];

fn main() { use std::f32; let f = 1.0f32; // atan(tan(1)) let abs_difference = (f.tan().atan() - 1.0).abs(); assert!(abs_difference <= f32::EPSILON); }

    use std::f32;

    let f = 1.0f32;

    // atan(tan(1))
    let abs_difference = (f.tan().atan() - 1.0).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn atan2(self, other: f32) -> f32`
1.0.0

Computes the four quadrant arctangent of `self` (`y`) and `other` (`x`).

- `x = 0`, `y = 0`: `0`
- `x >= 0`: `arctan(y/x)` -> `[-pi/2, pi/2]`
- `y >= 0`: `arctan(y/x) + pi` -> `(pi/2, pi]`
- `y < 0`: `arctan(y/x) - pi` -> `(-pi, -pi/2)`

fn main() { use std::f32; let pi = f32::consts::PI; // All angles from horizontal right (+x) // 45 deg counter-clockwise let x1 = 3.0f32; let y1 = -3.0f32; // 135 deg clockwise let x2 = -3.0f32; let y2 = 3.0f32; let abs_difference_1 = (y1.atan2(x1) - (-pi/4.0)).abs(); let abs_difference_2 = (y2.atan2(x2) - 3.0*pi/4.0).abs(); assert!(abs_difference_1 <= f32::EPSILON); assert!(abs_difference_2 <= f32::EPSILON); }

    use std::f32;

    let pi = f32::consts::PI;
    // All angles from horizontal right (+x)
    // 45 deg counter-clockwise
    let x1 = 3.0f32;
    let y1 = -3.0f32;

    // 135 deg clockwise
    let x2 = -3.0f32;
    let y2 = 3.0f32;

    let abs_difference_1 = (y1.atan2(x1) - (-pi/4.0)).abs();
    let abs_difference_2 = (y2.atan2(x2) - 3.0*pi/4.0).abs();

    assert!(abs_difference_1 <= f32::EPSILON);
    assert!(abs_difference_2 <= f32::EPSILON);

#### `fn sin_cos(self) -> (f32, f32)`
1.0.0

Simultaneously computes the sine and cosine of the number, `x`. Returns `(sin(x), cos(x))`.

fn main() { use std::f32; let x = f32::consts::PI/4.0; let f = x.sin_cos(); let abs_difference_0 = (f.0 - x.sin()).abs(); let abs_difference_1 = (f.1 - x.cos()).abs(); assert!(abs_difference_0 <= f32::EPSILON); assert!(abs_difference_1 <= f32::EPSILON); }

    use std::f32;

    let x = f32::consts::PI/4.0;
    let f = x.sin_cos();

    let abs_difference_0 = (f.0 - x.sin()).abs();
    let abs_difference_1 = (f.1 - x.cos()).abs();

    assert!(abs_difference_0 <= f32::EPSILON);
    assert!(abs_difference_1 <= f32::EPSILON);

#### `fn exp_m1(self) -> f32`
1.0.0

Returns `e^(self) - 1` in a way that is accurate even if the number is close to zero.

fn main() { use std::f32; let x = 6.0f32; // e^(ln(6)) - 1 let abs_difference = (x.ln().exp_m1() - 5.0).abs(); assert!(abs_difference <= f32::EPSILON); }

    use std::f32;

    let x = 6.0f32;

    // e^(ln(6)) - 1
    let abs_difference = (x.ln().exp_m1() - 5.0).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn ln_1p(self) -> f32`
1.0.0

Returns `ln(1+n)` (natural logarithm) more accurately than if the operations were performed separately.

fn main() { use std::f32; let x = f32::consts::E - 1.0; // ln(1 + (e - 1)) == ln(e) == 1 let abs_difference = (x.ln_1p() - 1.0).abs(); assert!(abs_difference <= f32::EPSILON); }

    use std::f32;

    let x = f32::consts::E - 1.0;

    // ln(1 + (e - 1)) == ln(e) == 1
    let abs_difference = (x.ln_1p() - 1.0).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn sinh(self) -> f32`
1.0.0

Hyperbolic sine function.

fn main() { use std::f32; let e = f32::consts::E; let x = 1.0f32; let f = x.sinh(); // Solving sinh() at 1 gives `(e^2-1)/(2e)` let g = (e*e - 1.0)/(2.0*e); let abs_difference = (f - g).abs(); assert!(abs_difference <= f32::EPSILON); }

    use std::f32;

    let e = f32::consts::E;
    let x = 1.0f32;

    let f = x.sinh();
    // Solving sinh() at 1 gives `(e^2-1)/(2e)`
    let g = (e*e - 1.0)/(2.0*e);
    let abs_difference = (f - g).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn cosh(self) -> f32`
1.0.0

Hyperbolic cosine function.

fn main() { use std::f32; let e = f32::consts::E; let x = 1.0f32; let f = x.cosh(); // Solving cosh() at 1 gives this result let g = (e*e + 1.0)/(2.0*e); let abs_difference = (f - g).abs(); // Same result assert!(abs_difference <= f32::EPSILON); }

    use std::f32;

    let e = f32::consts::E;
    let x = 1.0f32;
    let f = x.cosh();
    // Solving cosh() at 1 gives this result
    let g = (e*e + 1.0)/(2.0*e);
    let abs_difference = (f - g).abs();

    // Same result
    assert!(abs_difference <= f32::EPSILON);

#### `fn tanh(self) -> f32`
1.0.0

Hyperbolic tangent function.

fn main() { use std::f32; let e = f32::consts::E; let x = 1.0f32; let f = x.tanh(); // Solving tanh() at 1 gives `(1 - e^(-2))/(1 + e^(-2))` let g = (1.0 - e.powi(-2))/(1.0 + e.powi(-2)); let abs_difference = (f - g).abs(); assert!(abs_difference <= f32::EPSILON); }

    use std::f32;

    let e = f32::consts::E;
    let x = 1.0f32;

    let f = x.tanh();
    // Solving tanh() at 1 gives `(1 - e^(-2))/(1 + e^(-2))`
    let g = (1.0 - e.powi(-2))/(1.0 + e.powi(-2));
    let abs_difference = (f - g).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn asinh(self) -> f32`
1.0.0

Inverse hyperbolic sine function.

fn main() { use std::f32; let x = 1.0f32; let f = x.sinh().asinh(); let abs_difference = (f - x).abs(); assert!(abs_difference <= f32::EPSILON); }

    use std::f32;

    let x = 1.0f32;
    let f = x.sinh().asinh();

    let abs_difference = (f - x).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn acosh(self) -> f32`
1.0.0

Inverse hyperbolic cosine function.

fn main() { use std::f32; let x = 1.0f32; let f = x.cosh().acosh(); let abs_difference = (f - x).abs(); assert!(abs_difference <= f32::EPSILON); }

    use std::f32;

    let x = 1.0f32;
    let f = x.cosh().acosh();

    let abs_difference = (f - x).abs();

    assert!(abs_difference <= f32::EPSILON);

#### `fn atanh(self) -> f32`
1.0.0

Inverse hyperbolic tangent function.

fn main() { use std::f32; let e = f32::consts::E; let f = e.tanh().atanh(); let abs_difference = (f - e).abs(); assert!(abs_difference <= 1e-5); }

    use std::f32;

    let e = f32::consts::E;
    let f = e.tanh().atanh();

    let abs_difference = (f - e).abs();

    assert!(abs_difference <= 1e-5);

## Trait Implementations

### `impl FromStr for f32`
1.0.0

#### `type Err = ParseFloatError`

The associated error which can be returned from parsing.

#### `fn from_str(src: &str) -> Result<f32, ParseFloatError>`

Converts a string in base 10 to a float. Accepts an optional decimal exponent.

This function accepts strings such as

- '3.14'
- '-3.14'
- '2.5E10', or equivalently, '2.5e10'
- '2.5E-10'
- '.' (understood as 0)
- '5.'
- '.5', or, equivalently, '0.5'
- 'inf', '-inf', 'NaN'

Leading and trailing whitespace represent an error.

# Arguments

- src - A string

# Return value

`Err(ParseFloatError)` if the string did not represent a valid number. Otherwise, `Ok(n)` where `n` is the floating-point number represented by `src`.

### `impl Zero for f32`

#### `fn zero() -> f32`

Deprecated since 1.11.0

: no longer used for Iterator::sum

Unstable (`zero_one` #27739)

: no longer used for Iterator::sum

The "zero" (usually, additive identity) for this type.

### `impl One for f32`

#### `fn one() -> f32`

Deprecated since 1.11.0

: no longer used for Iterator::product

Unstable (`zero_one` #27739)

: no longer used for Iterator::product

The "one" (usually, multiplicative identity) for this type.

### `impl From<i8> for f32`
1.5.0

#### `fn from(small: i8) -> f32`

Performs the conversion.

### `impl From<i16> for f32`
1.5.0

#### `fn from(small: i16) -> f32`

Performs the conversion.

### `impl From<u8> for f32`
1.5.0

#### `fn from(small: u8) -> f32`

Performs the conversion.

### `impl From<u16> for f32`
1.5.0

#### `fn from(small: u16) -> f32`

Performs the conversion.

### `impl Add<f32> for f32`
1.0.0

#### `type Output = f32`

The resulting type after applying the `+` operator

#### `fn add(self, other: f32) -> f32`

The method for the `+` operator

### `impl<'a> Add<f32> for &'a f32`
1.0.0

#### `type Output = f32::Output`

The resulting type after applying the `+` operator

#### `fn add(self, other: f32) -> f32::Output`

The method for the `+` operator

### `impl<'a> Add<&'a f32> for f32`
1.0.0

#### `type Output = f32::Output`

The resulting type after applying the `+` operator

#### `fn add(self, other: &'a f32) -> f32::Output`

The method for the `+` operator

### `impl<'a, 'b> Add<&'a f32> for &'b f32`
1.0.0

#### `type Output = f32::Output`

The resulting type after applying the `+` operator

#### `fn add(self, other: &'a f32) -> f32::Output`

The method for the `+` operator

### `impl Sub<f32> for f32`
1.0.0

#### `type Output = f32`

The resulting type after applying the `-` operator

#### `fn sub(self, other: f32) -> f32`

The method for the `-` operator

### `impl<'a> Sub<f32> for &'a f32`
1.0.0

#### `type Output = f32::Output`

The resulting type after applying the `-` operator

#### `fn sub(self, other: f32) -> f32::Output`

The method for the `-` operator

### `impl<'a> Sub<&'a f32> for f32`
1.0.0

#### `type Output = f32::Output`

The resulting type after applying the `-` operator

#### `fn sub(self, other: &'a f32) -> f32::Output`

The method for the `-` operator

### `impl<'a, 'b> Sub<&'a f32> for &'b f32`
1.0.0

#### `type Output = f32::Output`

The resulting type after applying the `-` operator

#### `fn sub(self, other: &'a f32) -> f32::Output`

The method for the `-` operator

### `impl Mul<f32> for f32`
1.0.0

#### `type Output = f32`

The resulting type after applying the `*` operator

#### `fn mul(self, other: f32) -> f32`

The method for the `*` operator

### `impl<'a> Mul<f32> for &'a f32`
1.0.0

#### `type Output = f32::Output`

The resulting type after applying the `*` operator

#### `fn mul(self, other: f32) -> f32::Output`

The method for the `*` operator

### `impl<'a> Mul<&'a f32> for f32`
1.0.0

#### `type Output = f32::Output`

The resulting type after applying the `*` operator

#### `fn mul(self, other: &'a f32) -> f32::Output`

The method for the `*` operator

### `impl<'a, 'b> Mul<&'a f32> for &'b f32`
1.0.0

#### `type Output = f32::Output`

The resulting type after applying the `*` operator

#### `fn mul(self, other: &'a f32) -> f32::Output`

The method for the `*` operator

### `impl Div<f32> for f32`
1.0.0

#### `type Output = f32`

The resulting type after applying the `/` operator

#### `fn div(self, other: f32) -> f32`

The method for the `/` operator

### `impl<'a> Div<f32> for &'a f32`
1.0.0

#### `type Output = f32::Output`

The resulting type after applying the `/` operator

#### `fn div(self, other: f32) -> f32::Output`

The method for the `/` operator

### `impl<'a> Div<&'a f32> for f32`
1.0.0

#### `type Output = f32::Output`

The resulting type after applying the `/` operator

#### `fn div(self, other: &'a f32) -> f32::Output`

The method for the `/` operator

### `impl<'a, 'b> Div<&'a f32> for &'b f32`
1.0.0

#### `type Output = f32::Output`

The resulting type after applying the `/` operator

#### `fn div(self, other: &'a f32) -> f32::Output`

The method for the `/` operator

### `impl Rem<f32> for f32`
1.0.0

#### `type Output = f32`

The resulting type after applying the `%` operator

#### `fn rem(self, other: f32) -> f32`

The method for the `%` operator

### `impl<'a> Rem<f32> for &'a f32`
1.0.0

#### `type Output = f32::Output`

The resulting type after applying the `%` operator

#### `fn rem(self, other: f32) -> f32::Output`

The method for the `%` operator

### `impl<'a> Rem<&'a f32> for f32`
1.0.0

#### `type Output = f32::Output`

The resulting type after applying the `%` operator

#### `fn rem(self, other: &'a f32) -> f32::Output`

The method for the `%` operator

### `impl<'a, 'b> Rem<&'a f32> for &'b f32`
1.0.0

#### `type Output = f32::Output`

The resulting type after applying the `%` operator

#### `fn rem(self, other: &'a f32) -> f32::Output`

The method for the `%` operator

### `impl Neg for f32`
1.0.0

#### `type Output = f32`

The resulting type after applying the `-` operator

#### `fn neg(self) -> f32`

The method for the unary `-` operator

### `impl<'a> Neg for &'a f32`
1.0.0

#### `type Output = f32::Output`

The resulting type after applying the `-` operator

#### `fn neg(self) -> f32::Output`

The method for the unary `-` operator

### `impl AddAssign<f32> for f32`
1.8.0

#### `fn add_assign(&mut self, other: f32)`

The method for the `+=` operator

### `impl SubAssign<f32> for f32`
1.8.0

#### `fn sub_assign(&mut self, other: f32)`

The method for the `-=` operator

### `impl MulAssign<f32> for f32`
1.8.0

#### `fn mul_assign(&mut self, other: f32)`

The method for the `*=` operator

### `impl DivAssign<f32> for f32`
1.8.0

#### `fn div_assign(&mut self, other: f32)`

The method for the `/=` operator

### `impl RemAssign<f32> for f32`
1.8.0

#### `fn rem_assign(&mut self, other: f32)`

The method for the `%=` operator

### `impl PartialEq<f32> for f32`
1.0.0

#### `fn eq(&self, other: &f32) -> bool`

This method tests for `self` and `other` values to be equal, and is used by `==`. Read more

#### `fn ne(&self, other: &f32) -> bool`

This method tests for `!=`.

### `impl PartialOrd<f32> for f32`
1.0.0

#### `fn partial_cmp(&self, other: &f32) -> Option<Ordering>`

This method returns an ordering between `self` and `other` values if one exists. Read more

#### `fn lt(&self, other: &f32) -> bool`

This method tests less than (for `self` and `other`) and is used by the `<` operator. Read more

#### `fn le(&self, other: &f32) -> bool`

This method tests less than or equal to (for `self` and `other`) and is used by the `<=` operator. Read more

#### `fn ge(&self, other: &f32) -> bool`

This method tests greater than or equal to (for `self` and `other`) and is used by the `>=` operator. Read more

#### `fn gt(&self, other: &f32) -> bool`

This method tests greater than (for `self` and `other`) and is used by the `>` operator. Read more

### `impl Clone for f32`
1.0.0

#### `fn clone(&self) -> f32`

Returns a deep copy of the value.

#### `fn clone_from(&mut self, source: &Self)`
1.0.0

Performs copy-assignment from `source`. Read more

### `impl Default for f32`
1.0.0

#### `fn default() -> f32`

Returns the "default value" for a type. Read more

### `impl Sum<f32> for f32`

#### `fn sum<I>(iter: I) -> f32 where I: Iterator<Item=f32>`

Unstable (`iter_arith_traits` #34529)

Method which takes an iterator and generates `Self` from the elements by "summing up" the items. Read more

### `impl Product<f32> for f32`

#### `fn product<I>(iter: I) -> f32 where I: Iterator<Item=f32>`

Unstable (`iter_arith_traits` #34529)

Method which takes an iterator and generates `Self` from the elements by multiplying the items. Read more

### `impl<'a> Sum<&'a f32> for f32`

#### `fn sum<I>(iter: I) -> f32 where I: Iterator<Item=&'a f32>`

Unstable (`iter_arith_traits` #34529)

Method which takes an iterator and generates `Self` from the elements by "summing up" the items. Read more

### `impl<'a> Product<&'a f32> for f32`

#### `fn product<I>(iter: I) -> f32 where I: Iterator<Item=&'a f32>`

Unstable (`iter_arith_traits` #34529)

Method which takes an iterator and generates `Self` from the elements by multiplying the items. Read more

### `impl Debug for f32`
1.0.0

#### `fn fmt(&self, fmt: &mut Formatter) -> Result<(), Error>`

Formats the value using the given formatter.

### `impl Display for f32`
1.0.0

#### `fn fmt(&self, fmt: &mut Formatter) -> Result<(), Error>`

Formats the value using the given formatter.

### `impl LowerExp for f32`
1.0.0

#### `fn fmt(&self, fmt: &mut Formatter) -> Result<(), Error>`

Formats the value using the given formatter.

### `impl UpperExp for f32`
1.0.0

#### `fn fmt(&self, fmt: &mut Formatter) -> Result<(), Error>`

Formats the value using the given formatter.

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