Primitive Type f32 []

The 32-bit floating point type.

See also the std::f32 module.

Methods

impl f32
[src]

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());Run

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());Run

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());Run

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());Run

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);Run

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);Run

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);Run

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);Run

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);Run

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);Run

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);Run

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());Run

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());Run

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());Run

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());Run

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);Run

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);Run

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);Run

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);Run

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());Run

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);Run

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);Run

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);Run

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);Run

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);Run

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);Run

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);Run

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);Run

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);Run

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);Run

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);Run

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);Run

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

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);Run

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

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);Run

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);Run

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);Run

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);Run

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);Run

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);Run

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);Run

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);Run

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);Run

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);Run

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);Run

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);Run

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);Run

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);Run

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);Run

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);Run

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);Run

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);Run

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);Run

Trait Implementations

impl SubAssign<f32> for f32
1.8.0

The method for the -= operator

impl PartialEq<f32> for f32
1.0.0

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

This method tests for !=.

impl MulAssign<f32> for f32
1.8.0

The method for the *= operator

impl Default for f32
1.0.0

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

impl Clone for f32
1.0.0

Returns a deep copy of the value.

Performs copy-assignment from source. Read more

impl LowerExp for f32
1.0.0

Formats the value using the given formatter.

impl Display for f32
1.0.0

Formats the value using the given formatter.

impl Sum<f32> for f32
1.12.0

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

impl<'a> Sum<&'a f32> for f32
1.12.0

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

impl Neg for f32
1.0.0

The resulting type after applying the - operator

The method for the unary - operator

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

The resulting type after applying the - operator

The method for the unary - operator

impl Add<f32> for f32
1.0.0

The resulting type after applying the + operator

The method for the + operator

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

The resulting type after applying the + operator

The method for the + operator

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

The resulting type after applying the + operator

The method for the + operator

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

The resulting type after applying the + operator

The method for the + operator

impl From<i8> for f32
1.5.0

Performs the conversion.

impl From<i16> for f32
1.5.0

Performs the conversion.

impl From<u8> for f32
1.5.0

Performs the conversion.

impl From<u16> for f32
1.5.0

Performs the conversion.

impl Rem<f32> for f32
1.0.0

The resulting type after applying the % operator

The method for the % operator

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

The resulting type after applying the % operator

The method for the % operator

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

The resulting type after applying the % operator

The method for the % operator

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

The resulting type after applying the % operator

The method for the % operator

impl FromStr for f32
1.0.0

The associated error which can be returned from parsing.

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 Div<f32> for f32
1.0.0

The resulting type after applying the / operator

The method for the / operator

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

The resulting type after applying the / operator

The method for the / operator

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

The resulting type after applying the / operator

The method for the / operator

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

The resulting type after applying the / operator

The method for the / operator

impl One for 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 Debug for f32
1.0.0

Formats the value using the given formatter.

impl Mul<f32> for f32
1.0.0

The resulting type after applying the * operator

The method for the * operator

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

The resulting type after applying the * operator

The method for the * operator

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

The resulting type after applying the * operator

The method for the * operator

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

The resulting type after applying the * operator

The method for the * operator

impl Zero for 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 DivAssign<f32> for f32
1.8.0

The method for the /= operator

impl Sub<f32> for f32
1.0.0

The resulting type after applying the - operator

The method for the - operator

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

The resulting type after applying the - operator

The method for the - operator

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

The resulting type after applying the - operator

The method for the - operator

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

The resulting type after applying the - operator

The method for the - operator

impl PartialOrd<f32> for f32
1.0.0

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

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

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

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

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

impl RemAssign<f32> for f32
1.8.0

The method for the %= operator

impl UpperExp for f32
1.0.0

Formats the value using the given formatter.

impl AddAssign<f32> for f32
1.8.0

The method for the += operator

impl Product<f32> for f32
1.12.0

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

impl<'a> Product<&'a f32> for f32
1.12.0

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