Primitive Type f64 [-] [+]

Operations and constants for 64-bits floats (f64 type)

Methods

impl f64

fn from_str_radix(s: &str, radix: u32) -> Result<f64, ParseFloatError>

Parses a float as with a given radix

fn is_nan(self) -> bool

Returns true if this value is NaN and false otherwise.

extern crate std; fn main() { use std::f64; let nan = f64::NAN; let f = 7.0_f64; assert!(nan.is_nan()); assert!(!f.is_nan()); }
use std::f64;

let nan = f64::NAN;
let f = 7.0_f64;

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

fn is_infinite(self) -> bool

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

extern crate std; fn main() { use std::f64; let f = 7.0f64; let inf = f64::INFINITY; let neg_inf = f64::NEG_INFINITY; let nan = f64::NAN; assert!(!f.is_infinite()); assert!(!nan.is_infinite()); assert!(inf.is_infinite()); assert!(neg_inf.is_infinite()); }
use std::f64;

let f = 7.0f64;
let inf = f64::INFINITY;
let neg_inf = f64::NEG_INFINITY;
let nan = f64::NAN;

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

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

fn is_finite(self) -> bool

Returns true if this number is neither infinite nor NaN.

extern crate std; fn main() { use std::f64; let f = 7.0f64; let inf: f64 = f64::INFINITY; let neg_inf: f64 = f64::NEG_INFINITY; let nan: f64 = f64::NAN; assert!(f.is_finite()); assert!(!nan.is_finite()); assert!(!inf.is_finite()); assert!(!neg_inf.is_finite()); }
use std::f64;

let f = 7.0f64;
let inf: f64 = f64::INFINITY;
let neg_inf: f64 = f64::NEG_INFINITY;
let nan: f64 = f64::NAN;

assert!(f.is_finite());

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

fn is_normal(self) -> bool

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

extern crate std; fn main() { use std::f32; let min = f32::MIN_POSITIVE; // 1.17549435e-38f64 let max = f32::MAX; let lower_than_min = 1.0e-40_f32; let zero = 0.0f32; 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-38f64
let max = f32::MAX;
let lower_than_min = 1.0e-40_f32;
let zero = 0.0f32;

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

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.

extern crate std; fn main() { use std::num::FpCategory; use std::f64; let num = 12.4_f64; let inf = f64::INFINITY; assert_eq!(num.classify(), FpCategory::Normal); assert_eq!(inf.classify(), FpCategory::Infinite); }
use std::num::FpCategory;
use std::f64;

let num = 12.4_f64;
let inf = f64::INFINITY;

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

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

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(std_misc)] extern crate std; fn main() { let num = 2.0f64; // (8388608, -22, 1) let (mantissa, exponent, sign) = num.integer_decode(); let sign_f = sign as f64; let mantissa_f = mantissa as f64; let exponent_f = num.powf(exponent as f64); // 1 * 8388608 * 2^(-22) == 2 let abs_difference = (sign_f * mantissa_f * exponent_f - num).abs(); assert!(abs_difference < 1e-10); }
let num = 2.0f64;

// (8388608, -22, 1)
let (mantissa, exponent, sign) = num.integer_decode();
let sign_f = sign as f64;
let mantissa_f = mantissa as f64;
let exponent_f = num.powf(exponent as f64);

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

assert!(abs_difference < 1e-10);

fn floor(self) -> f64

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

fn main() { let f = 3.99_f64; let g = 3.0_f64; assert_eq!(f.floor(), 3.0); assert_eq!(g.floor(), 3.0); }
let f = 3.99_f64;
let g = 3.0_f64;

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

fn ceil(self) -> f64

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

fn main() { let f = 3.01_f64; let g = 4.0_f64; assert_eq!(f.ceil(), 4.0); assert_eq!(g.ceil(), 4.0); }
let f = 3.01_f64;
let g = 4.0_f64;

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

fn round(self) -> f64

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

fn main() { let f = 3.3_f64; let g = -3.3_f64; assert_eq!(f.round(), 3.0); assert_eq!(g.round(), -3.0); }
let f = 3.3_f64;
let g = -3.3_f64;

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

fn trunc(self) -> f64

Returns the integer part of a number.

fn main() { let f = 3.3_f64; let g = -3.7_f64; assert_eq!(f.trunc(), 3.0); assert_eq!(g.trunc(), -3.0); }
let f = 3.3_f64;
let g = -3.7_f64;

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

fn fract(self) -> f64

Returns the fractional part of a number.

fn main() { let x = 3.5_f64; let y = -3.5_f64; let abs_difference_x = (x.fract() - 0.5).abs(); let abs_difference_y = (y.fract() - (-0.5)).abs(); assert!(abs_difference_x < 1e-10); assert!(abs_difference_y < 1e-10); }
let x = 3.5_f64;
let y = -3.5_f64;
let abs_difference_x = (x.fract() - 0.5).abs();
let abs_difference_y = (y.fract() - (-0.5)).abs();

assert!(abs_difference_x < 1e-10);
assert!(abs_difference_y < 1e-10);

fn abs(self) -> f64

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

extern crate std; fn main() { use std::f64; let x = 3.5_f64; let y = -3.5_f64; let abs_difference_x = (x.abs() - x).abs(); let abs_difference_y = (y.abs() - (-y)).abs(); assert!(abs_difference_x < 1e-10); assert!(abs_difference_y < 1e-10); assert!(f64::NAN.abs().is_nan()); }
use std::f64;

let x = 3.5_f64;
let y = -3.5_f64;

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

assert!(abs_difference_x < 1e-10);
assert!(abs_difference_y < 1e-10);

assert!(f64::NAN.abs().is_nan());

fn signum(self) -> f64

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
extern crate std; fn main() { use std::f64; let f = 3.5_f64; assert_eq!(f.signum(), 1.0); assert_eq!(f64::NEG_INFINITY.signum(), -1.0); assert!(f64::NAN.signum().is_nan()); }
use std::f64;

let f = 3.5_f64;

assert_eq!(f.signum(), 1.0);
assert_eq!(f64::NEG_INFINITY.signum(), -1.0);

assert!(f64::NAN.signum().is_nan());

fn is_sign_positive(self) -> bool

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

extern crate std; fn main() { use std::f64; let nan: f64 = f64::NAN; let f = 7.0_f64; let g = -7.0_f64; 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::f64;

let nan: f64 = f64::NAN;

let f = 7.0_f64;
let g = -7.0_f64;

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_positive(self) -> bool

fn is_sign_negative(self) -> bool

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

extern crate std; fn main() { use std::f64; let nan = f64::NAN; let f = 7.0_f64; let g = -7.0_f64; 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::f64;

let nan = f64::NAN;

let f = 7.0_f64;
let g = -7.0_f64;

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 is_negative(self) -> bool

fn mul_add(self, a: f64, b: f64) -> f64

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() { let m = 10.0_f64; let x = 4.0_f64; let b = 60.0_f64; // 100.0 let abs_difference = (m.mul_add(x, b) - (m*x + b)).abs(); assert!(abs_difference < 1e-10); }
let m = 10.0_f64;
let x = 4.0_f64;
let b = 60.0_f64;

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

assert!(abs_difference < 1e-10);

fn recip(self) -> f64

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

fn main() { let x = 2.0_f64; let abs_difference = (x.recip() - (1.0/x)).abs(); assert!(abs_difference < 1e-10); }
let x = 2.0_f64;
let abs_difference = (x.recip() - (1.0/x)).abs();

assert!(abs_difference < 1e-10);

fn powi(self, n: i32) -> f64

Raises a number to an integer power.

Using this function is generally faster than using powf

fn main() { let x = 2.0_f64; let abs_difference = (x.powi(2) - x*x).abs(); assert!(abs_difference < 1e-10); }
let x = 2.0_f64;
let abs_difference = (x.powi(2) - x*x).abs();

assert!(abs_difference < 1e-10);

fn powf(self, n: f64) -> f64

Raises a number to a floating point power.

fn main() { let x = 2.0_f64; let abs_difference = (x.powf(2.0) - x*x).abs(); assert!(abs_difference < 1e-10); }
let x = 2.0_f64;
let abs_difference = (x.powf(2.0) - x*x).abs();

assert!(abs_difference < 1e-10);

fn sqrt(self) -> f64

Takes the square root of a number.

Returns NaN if self is a negative number.

fn main() { let positive = 4.0_f64; let negative = -4.0_f64; let abs_difference = (positive.sqrt() - 2.0).abs(); assert!(abs_difference < 1e-10); assert!(negative.sqrt().is_nan()); }
let positive = 4.0_f64;
let negative = -4.0_f64;

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

assert!(abs_difference < 1e-10);
assert!(negative.sqrt().is_nan());

fn exp(self) -> f64

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

fn main() { let one = 1.0_f64; // e^1 let e = one.exp(); // ln(e) - 1 == 0 let abs_difference = (e.ln() - 1.0).abs(); assert!(abs_difference < 1e-10); }
let one = 1.0_f64;
// e^1
let e = one.exp();

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

assert!(abs_difference < 1e-10);

fn exp2(self) -> f64

Returns 2^(self).

fn main() { let f = 2.0_f64; // 2^2 - 4 == 0 let abs_difference = (f.exp2() - 4.0).abs(); assert!(abs_difference < 1e-10); }
let f = 2.0_f64;

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

assert!(abs_difference < 1e-10);

fn ln(self) -> f64

Returns the natural logarithm of the number.

fn main() { let one = 1.0_f64; // e^1 let e = one.exp(); // ln(e) - 1 == 0 let abs_difference = (e.ln() - 1.0).abs(); assert!(abs_difference < 1e-10); }
let one = 1.0_f64;
// e^1
let e = one.exp();

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

assert!(abs_difference < 1e-10);

fn log(self, base: f64) -> f64

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

fn main() { let ten = 10.0_f64; let two = 2.0_f64; // 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 < 1e-10); assert!(abs_difference_2 < 1e-10); }
let ten = 10.0_f64;
let two = 2.0_f64;

// 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 < 1e-10);
assert!(abs_difference_2 < 1e-10);

fn log2(self) -> f64

Returns the base 2 logarithm of the number.

fn main() { let two = 2.0_f64; // log2(2) - 1 == 0 let abs_difference = (two.log2() - 1.0).abs(); assert!(abs_difference < 1e-10); }
let two = 2.0_f64;

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

assert!(abs_difference < 1e-10);

fn log10(self) -> f64

Returns the base 10 logarithm of the number.

fn main() { let ten = 10.0_f64; // log10(10) - 1 == 0 let abs_difference = (ten.log10() - 1.0).abs(); assert!(abs_difference < 1e-10); }
let ten = 10.0_f64;

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

assert!(abs_difference < 1e-10);

fn to_degrees(self) -> f64

Converts radians to degrees.

extern crate std; fn main() { use std::f64::consts; let angle = consts::PI; let abs_difference = (angle.to_degrees() - 180.0).abs(); assert!(abs_difference < 1e-10); }
use std::f64::consts;

let angle = consts::PI;

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

assert!(abs_difference < 1e-10);

fn to_radians(self) -> f64

Converts degrees to radians.

extern crate std; fn main() { use std::f64::consts; let angle = 180.0_f64; let abs_difference = (angle.to_radians() - consts::PI).abs(); assert!(abs_difference < 1e-10); }
use std::f64::consts;

let angle = 180.0_f64;

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

assert!(abs_difference < 1e-10);

fn ldexp(x: f64, exp: isize) -> f64

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

#![feature(std_misc)] extern crate std; fn main() { // 3*2^2 - 12 == 0 let abs_difference = (f64::ldexp(3.0, 2) - 12.0).abs(); assert!(abs_difference < 1e-10); }
// 3*2^2 - 12 == 0
let abs_difference = (f64::ldexp(3.0, 2) - 12.0).abs();

assert!(abs_difference < 1e-10);

fn frexp(self) -> (f64, isize)

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

  • self = x * 2^exp
  • 0.5 <= abs(x) < 1.0
#![feature(std_misc)] extern crate std; fn main() { let x = 4.0_f64; // (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 f64 - 3.0).abs(); assert!(abs_difference_0 < 1e-10); assert!(abs_difference_1 < 1e-10); }
let x = 4.0_f64;

// (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 f64 - 3.0).abs();

assert!(abs_difference_0 < 1e-10);
assert!(abs_difference_1 < 1e-10);

fn next_after(self, other: f64) -> f64

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

#![feature(std_misc)] extern crate std; fn main() { let x = 1.0f32; let abs_diff = (x.next_after(2.0) - 1.00000011920928955078125_f32).abs(); assert!(abs_diff < 1e-10); }

let x = 1.0f32;

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

assert!(abs_diff < 1e-10);

fn max(self, other: f64) -> f64

Returns the maximum of the two numbers.

fn main() { let x = 1.0_f64; let y = 2.0_f64; assert_eq!(x.max(y), y); }
let x = 1.0_f64;
let y = 2.0_f64;

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

fn min(self, other: f64) -> f64

Returns the minimum of the two numbers.

fn main() { let x = 1.0_f64; let y = 2.0_f64; assert_eq!(x.min(y), x); }
let x = 1.0_f64;
let y = 2.0_f64;

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

fn abs_sub(self, other: f64) -> f64

The positive difference of two numbers.

  • If self <= other: 0:0
  • Else: self - other
fn main() { let x = 3.0_f64; let y = -3.0_f64; 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 < 1e-10); assert!(abs_difference_y < 1e-10); }
let x = 3.0_f64;
let y = -3.0_f64;

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 < 1e-10);
assert!(abs_difference_y < 1e-10);

fn cbrt(self) -> f64

Takes the cubic root of a number.

fn main() { let x = 8.0_f64; // x^(1/3) - 2 == 0 let abs_difference = (x.cbrt() - 2.0).abs(); assert!(abs_difference < 1e-10); }
let x = 8.0_f64;

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

assert!(abs_difference < 1e-10);

fn hypot(self, other: f64) -> f64

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

fn main() { let x = 2.0_f64; let y = 3.0_f64; // sqrt(x^2 + y^2) let abs_difference = (x.hypot(y) - (x.powi(2) + y.powi(2)).sqrt()).abs(); assert!(abs_difference < 1e-10); }
let x = 2.0_f64;
let y = 3.0_f64;

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

assert!(abs_difference < 1e-10);

fn sin(self) -> f64

Computes the sine of a number (in radians).

extern crate std; fn main() { use std::f64; let x = f64::consts::PI/2.0; let abs_difference = (x.sin() - 1.0).abs(); assert!(abs_difference < 1e-10); }
use std::f64;

let x = f64::consts::PI/2.0;

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

assert!(abs_difference < 1e-10);

fn cos(self) -> f64

Computes the cosine of a number (in radians).

extern crate std; fn main() { use std::f64; let x = 2.0*f64::consts::PI; let abs_difference = (x.cos() - 1.0).abs(); assert!(abs_difference < 1e-10); }
use std::f64;

let x = 2.0*f64::consts::PI;

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

assert!(abs_difference < 1e-10);

fn tan(self) -> f64

Computes the tangent of a number (in radians).

extern crate std; fn main() { use std::f64; let x = f64::consts::PI/4.0; let abs_difference = (x.tan() - 1.0).abs(); assert!(abs_difference < 1e-14); }
use std::f64;

let x = f64::consts::PI/4.0;
let abs_difference = (x.tan() - 1.0).abs();

assert!(abs_difference < 1e-14);

fn asin(self) -> f64

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].

extern crate std; fn main() { use std::f64; let f = f64::consts::PI / 2.0; // asin(sin(pi/2)) let abs_difference = (f.sin().asin() - f64::consts::PI / 2.0).abs(); assert!(abs_difference < 1e-10); }
use std::f64;

let f = f64::consts::PI / 2.0;

// asin(sin(pi/2))
let abs_difference = (f.sin().asin() - f64::consts::PI / 2.0).abs();

assert!(abs_difference < 1e-10);

fn acos(self) -> f64

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].

extern crate std; fn main() { use std::f64; let f = f64::consts::PI / 4.0; // acos(cos(pi/4)) let abs_difference = (f.cos().acos() - f64::consts::PI / 4.0).abs(); assert!(abs_difference < 1e-10); }
use std::f64;

let f = f64::consts::PI / 4.0;

// acos(cos(pi/4))
let abs_difference = (f.cos().acos() - f64::consts::PI / 4.0).abs();

assert!(abs_difference < 1e-10);

fn atan(self) -> f64

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

fn main() { let f = 1.0_f64; // atan(tan(1)) let abs_difference = (f.tan().atan() - 1.0).abs(); assert!(abs_difference < 1e-10); }
let f = 1.0_f64;

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

assert!(abs_difference < 1e-10);

fn atan2(self, other: f64) -> f64

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)
extern crate std; fn main() { use std::f64; let pi = f64::consts::PI; // All angles from horizontal right (+x) // 45 deg counter-clockwise let x1 = 3.0_f64; let y1 = -3.0_f64; // 135 deg clockwise let x2 = -3.0_f64; let y2 = 3.0_f64; 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 < 1e-10); assert!(abs_difference_2 < 1e-10); }
use std::f64;

let pi = f64::consts::PI;
// All angles from horizontal right (+x)
// 45 deg counter-clockwise
let x1 = 3.0_f64;
let y1 = -3.0_f64;

// 135 deg clockwise
let x2 = -3.0_f64;
let y2 = 3.0_f64;

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 < 1e-10);
assert!(abs_difference_2 < 1e-10);

fn sin_cos(self) -> (f64, f64)

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

extern crate std; fn main() { use std::f64; let x = f64::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 < 1e-10); assert!(abs_difference_0 < 1e-10); }
use std::f64;

let x = f64::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 < 1e-10);
assert!(abs_difference_0 < 1e-10);

fn exp_m1(self) -> f64

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

fn main() { let x = 7.0_f64; // e^(ln(7)) - 1 let abs_difference = (x.ln().exp_m1() - 6.0).abs(); assert!(abs_difference < 1e-10); }
let x = 7.0_f64;

// e^(ln(7)) - 1
let abs_difference = (x.ln().exp_m1() - 6.0).abs();

assert!(abs_difference < 1e-10);

fn ln_1p(self) -> f64

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

extern crate std; fn main() { use std::f64; let x = f64::consts::E - 1.0; // ln(1 + (e - 1)) == ln(e) == 1 let abs_difference = (x.ln_1p() - 1.0).abs(); assert!(abs_difference < 1e-10); }
use std::f64;

let x = f64::consts::E - 1.0;

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

assert!(abs_difference < 1e-10);

fn sinh(self) -> f64

Hyperbolic sine function.

extern crate std; fn main() { use std::f64; let e = f64::consts::E; let x = 1.0_f64; 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 < 1e-10); }
use std::f64;

let e = f64::consts::E;
let x = 1.0_f64;

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 < 1e-10);

fn cosh(self) -> f64

Hyperbolic cosine function.

extern crate std; fn main() { use std::f64; let e = f64::consts::E; let x = 1.0_f64; 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 < 1.0e-10); }
use std::f64;

let e = f64::consts::E;
let x = 1.0_f64;
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 < 1.0e-10);

fn tanh(self) -> f64

Hyperbolic tangent function.

extern crate std; fn main() { use std::f64; let e = f64::consts::E; let x = 1.0_f64; 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 < 1.0e-10); }
use std::f64;

let e = f64::consts::E;
let x = 1.0_f64;

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 < 1.0e-10);

fn asinh(self) -> f64

Inverse hyperbolic sine function.

fn main() { let x = 1.0_f64; let f = x.sinh().asinh(); let abs_difference = (f - x).abs(); assert!(abs_difference < 1.0e-10); }
let x = 1.0_f64;
let f = x.sinh().asinh();

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

assert!(abs_difference < 1.0e-10);

fn acosh(self) -> f64

Inverse hyperbolic cosine function.

fn main() { let x = 1.0_f64; let f = x.cosh().acosh(); let abs_difference = (f - x).abs(); assert!(abs_difference < 1.0e-10); }
let x = 1.0_f64;
let f = x.cosh().acosh();

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

assert!(abs_difference < 1.0e-10);

fn atanh(self) -> f64

Inverse hyperbolic tangent function.

extern crate std; fn main() { use std::f64; let e = f64::consts::E; let f = e.tanh().atanh(); let abs_difference = (f - e).abs(); assert!(abs_difference < 1.0e-10); }
use std::f64;

let e = f64::consts::E;
let f = e.tanh().atanh();

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

assert!(abs_difference < 1.0e-10);

Trait Implementations

impl Zero for f64

fn zero() -> f64

impl One for f64

fn one() -> f64

impl FromStr for f64

type Err = ParseFloatError

fn from_str(src: &str) -> Result<f64, 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', equivalent to '3.14'
  • '-3.14'
  • '2.5E10', or equivalently, '2.5e10'
  • '2.5E-10'
  • '.' (understood as 0)
  • '5.'
  • '.5', or, equivalently, '0.5'
  • '+inf', '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 Add<f64> for f64

type Output = f64

fn add(self, other: f64) -> f64

impl<'a> Add<f64> for &'a f64

type Output = f64::Output

fn add(self, other: f64) -> f64::Output

impl<'a> Add<&'a f64> for f64

type Output = f64::Output

fn add(self, other: &'a f64) -> f64::Output

impl<'a, 'b> Add<&'a f64> for &'b f64

type Output = f64::Output

fn add(self, other: &'a f64) -> f64::Output

impl Sub<f64> for f64

type Output = f64

fn sub(self, other: f64) -> f64

impl<'a> Sub<f64> for &'a f64

type Output = f64::Output

fn sub(self, other: f64) -> f64::Output

impl<'a> Sub<&'a f64> for f64

type Output = f64::Output

fn sub(self, other: &'a f64) -> f64::Output

impl<'a, 'b> Sub<&'a f64> for &'b f64

type Output = f64::Output

fn sub(self, other: &'a f64) -> f64::Output

impl Mul<f64> for f64

type Output = f64

fn mul(self, other: f64) -> f64

impl<'a> Mul<f64> for &'a f64

type Output = f64::Output

fn mul(self, other: f64) -> f64::Output

impl<'a> Mul<&'a f64> for f64

type Output = f64::Output

fn mul(self, other: &'a f64) -> f64::Output

impl<'a, 'b> Mul<&'a f64> for &'b f64

type Output = f64::Output

fn mul(self, other: &'a f64) -> f64::Output

impl Div<f64> for f64

type Output = f64

fn div(self, other: f64) -> f64

impl<'a> Div<f64> for &'a f64

type Output = f64::Output

fn div(self, other: f64) -> f64::Output

impl<'a> Div<&'a f64> for f64

type Output = f64::Output

fn div(self, other: &'a f64) -> f64::Output

impl<'a, 'b> Div<&'a f64> for &'b f64

type Output = f64::Output

fn div(self, other: &'a f64) -> f64::Output

impl Rem<f64> for f64

type Output = f64

fn rem(self, other: f64) -> f64

impl<'a> Rem<f64> for &'a f64

type Output = f64::Output

fn rem(self, other: f64) -> f64::Output

impl<'a> Rem<&'a f64> for f64

type Output = f64::Output

fn rem(self, other: &'a f64) -> f64::Output

impl<'a, 'b> Rem<&'a f64> for &'b f64

type Output = f64::Output

fn rem(self, other: &'a f64) -> f64::Output

impl Neg for f64

type Output = f64

fn neg(self) -> f64

impl<'a> Neg for &'a f64

type Output = f64::Output

fn neg(self) -> f64::Output

impl PartialEq<f64> for f64

fn eq(&self, other: &f64) -> bool

fn ne(&self, other: &f64) -> bool

impl PartialOrd<f64> for f64

fn partial_cmp(&self, other: &f64) -> Option<Ordering>

fn lt(&self, other: &f64) -> bool

fn le(&self, other: &f64) -> bool

fn ge(&self, other: &f64) -> bool

fn gt(&self, other: &f64) -> bool

impl Clone for f64

fn clone(&self) -> f64

Returns a deep copy of the value.

fn clone_from(&mut self, source: &Self)

impl Default for f64

fn default() -> f64

impl Debug for f64

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

impl Display for f64

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

impl LowerExp for f64

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

impl UpperExp for f64

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

impl SampleRange for f64

fn construct_range(low: f64, high: f64) -> Range<f64>

fn sample_range<R>(r: &Range<f64>, rng: &mut R) -> f64 where R: Rng

impl Rand for f64

fn rand<R>(rng: &mut R) -> f64 where R: Rng

Generate a floating point number in the half-open interval [0,1).

See Closed01 for the closed interval [0,1], and Open01 for the open interval (0,1).