`impl f64`[src]

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn floor(self) -> f64[src][−]

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

Examples

let f = 3.7_f64;
let g = 3.0_f64;
let h = -3.7_f64;

assert_eq!(f.floor(), 3.0);
assert_eq!(g.floor(), 3.0);
assert_eq!(h.floor(), -4.0);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn ceil(self) -> f64[src][−]

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

Examples

let f = 3.01_f64;
let g = 4.0_f64;

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

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn round(self) -> f64[src][−]

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

Examples

let f = 3.3_f64;
let g = -3.3_f64;

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

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn trunc(self) -> f64[src][−]

Returns the integer part of a number.

Examples

let f = 3.7_f64;
let g = 3.0_f64;
let h = -3.7_f64;

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

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn fract(self) -> f64[src][−]

Returns the fractional part of a number.

Examples

let x = 3.6_f64;
let y = -3.6_f64;
let abs_difference_x = (x.fract() - 0.6).abs();
let abs_difference_y = (y.fract() - (-0.6)).abs();

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

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn abs(self) -> f64[src][−]

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

Examples

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());

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn signum(self) -> f64[src][−]

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

Examples

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());

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn copysign(self, sign: f64) -> f641.35.0[src][−]

Returns a number composed of the magnitude of self and the sign of sign.

Equal to self if the sign of self and sign are the same, otherwise equal to -self. If self is a NAN, then a NAN with the sign of sign is returned.

Examples

let f = 3.5_f64;

assert_eq!(f.copysign(0.42), 3.5_f64);
assert_eq!(f.copysign(-0.42), -3.5_f64);
assert_eq!((-f).copysign(0.42), 3.5_f64);
assert_eq!((-f).copysign(-0.42), -3.5_f64);

assert!(f64::NAN.copysign(1.0).is_nan());

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn mul_add(self, a: f64, b: f64) -> f64[src][−]

Fused multiply-add. Computes (self * a) + b with only one rounding error, yielding a more accurate result than an unfused multiply-add.

Using mul_add may be more performant than an unfused multiply-add if the target architecture has a dedicated fma CPU instruction. However, this is not always true, and will be heavily dependant on designing algorithms with specific target hardware in mind.

Examples

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);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn div_euclid(self, rhs: f64) -> f641.38.0[src][−]

Calculates Euclidean division, the matching method for rem_euclid.

This computes the integer n such that self = n * rhs + self.rem_euclid(rhs). In other words, the result is self / rhs rounded to the integer n such that self >= n * rhs.

Examples

let a: f64 = 7.0;
let b = 4.0;
assert_eq!(a.div_euclid(b), 1.0); // 7.0 > 4.0 * 1.0
assert_eq!((-a).div_euclid(b), -2.0); // -7.0 >= 4.0 * -2.0
assert_eq!(a.div_euclid(-b), -1.0); // 7.0 >= -4.0 * -1.0
assert_eq!((-a).div_euclid(-b), 2.0); // -7.0 >= -4.0 * 2.0

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn rem_euclid(self, rhs: f64) -> f641.38.0[src][−]

Calculates the least nonnegative remainder of self (mod rhs).

In particular, the return value r satisfies 0.0 <= r < rhs.abs() in most cases. However, due to a floating point round-off error it can result in r == rhs.abs(), violating the mathematical definition, if self is much smaller than rhs.abs() in magnitude and self < 0.0. This result is not an element of the function’s codomain, but it is the closest floating point number in the real numbers and thus fulfills the property self == self.div_euclid(rhs) * rhs + self.rem_euclid(rhs) approximatively.

Examples

let a: f64 = 7.0;
let b = 4.0;
assert_eq!(a.rem_euclid(b), 3.0);
assert_eq!((-a).rem_euclid(b), 1.0);
assert_eq!(a.rem_euclid(-b), 3.0);
assert_eq!((-a).rem_euclid(-b), 1.0);
// limitation due to round-off error
assert!((-f64::EPSILON).rem_euclid(3.0) != 0.0);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn powi(self, n: i32) -> f64[src][−]

Raises a number to an integer power.

Using this function is generally faster than using powf

Examples

let x = 2.0_f64;
let abs_difference = (x.powi(2) - (x * x)).abs();

assert!(abs_difference < 1e-10);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn powf(self, n: f64) -> f64[src][−]

Raises a number to a floating point power.

Examples

let x = 2.0_f64;
let abs_difference = (x.powf(2.0) - (x * x)).abs();

assert!(abs_difference < 1e-10);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn sqrt(self) -> f64[src][−]

Returns the square root of a number.

Returns NaN if self is a negative number.

Examples

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());

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn exp(self) -> f64[src][−]

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

Examples

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);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn exp2(self) -> f64[src][−]

Returns 2^(self).

Examples

let f = 2.0_f64;

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

assert!(abs_difference < 1e-10);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn ln(self) -> f64[src][−]

Returns the natural logarithm of the number.

Examples

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);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn log(self, base: f64) -> f64[src][−]

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

The result may not be correctly rounded owing to implementation details; self.log2() can produce more accurate results for base 2, and self.log10() can produce more accurate results for base 10.

Examples

let twenty_five = 25.0_f64;

// log5(25) - 2 == 0
let abs_difference = (twenty_five.log(5.0) - 2.0).abs();

assert!(abs_difference < 1e-10);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn log2(self) -> f64[src][−]

Returns the base 2 logarithm of the number.

Examples

let four = 4.0_f64;

// log2(4) - 2 == 0
let abs_difference = (four.log2() - 2.0).abs();

assert!(abs_difference < 1e-10);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn log10(self) -> f64[src][−]

Returns the base 10 logarithm of the number.

Examples

let hundred = 100.0_f64;

// log10(100) - 2 == 0
let abs_difference = (hundred.log10() - 2.0).abs();

assert!(abs_difference < 1e-10);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn abs_sub(self, other: f64) -> f64[src][−]

👎 Deprecated since 1.10.0:

you probably meant (self - other).abs(): this operation is (self - other).max(0.0) except that abs_sub also propagates NaNs (also known as fdim in C). If you truly need the positive difference, consider using that expression or the C function fdim, 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

Examples

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);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn cbrt(self) -> f64[src][−]

Returns the cube root of a number.

Examples

let x = 8.0_f64;

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

assert!(abs_difference < 1e-10);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn hypot(self, other: f64) -> f64[src][−]

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

Examples

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);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn sin(self) -> f64[src][−]

Computes the sine of a number (in radians).

Examples

let x = std::f64::consts::FRAC_PI_2;

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

assert!(abs_difference < 1e-10);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn cos(self) -> f64[src][−]

Computes the cosine of a number (in radians).

Examples

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

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

assert!(abs_difference < 1e-10);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn tan(self) -> f64[src][−]

Computes the tangent of a number (in radians).

Examples

let x = std::f64::consts::FRAC_PI_4;
let abs_difference = (x.tan() - 1.0).abs();

assert!(abs_difference < 1e-14);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn asin(self) -> f64[src][−]

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].

Examples

let f = std::f64::consts::FRAC_PI_2;

// asin(sin(pi/2))
let abs_difference = (f.sin().asin() - std::f64::consts::FRAC_PI_2).abs();

assert!(abs_difference < 1e-10);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn acos(self) -> f64[src][−]

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].

Examples

let f = std::f64::consts::FRAC_PI_4;

// acos(cos(pi/4))
let abs_difference = (f.cos().acos() - std::f64::consts::FRAC_PI_4).abs();

assert!(abs_difference < 1e-10);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn atan(self) -> f64[src][−]

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

Examples

let f = 1.0_f64;

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

assert!(abs_difference < 1e-10);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn atan2(self, other: f64) -> f64[src][−]

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

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)

Examples

// Positive angles measured counter-clockwise
// from positive x axis
// -pi/4 radians (45 deg clockwise)
let x1 = 3.0_f64;
let y1 = -3.0_f64;

// 3pi/4 radians (135 deg counter-clockwise)
let x2 = -3.0_f64;
let y2 = 3.0_f64;

let abs_difference_1 = (y1.atan2(x1) - (-std::f64::consts::FRAC_PI_4)).abs();
let abs_difference_2 = (y2.atan2(x2) - (3.0 * std::f64::consts::FRAC_PI_4)).abs();

assert!(abs_difference_1 < 1e-10);
assert!(abs_difference_2 < 1e-10);

Run

`pub fn sin_cos(self) -> (f64, f64)`[src][−]

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

Examples

let x = std::f64::consts::FRAC_PI_4;
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_1 < 1e-10);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn exp_m1(self) -> f64[src][−]

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

Examples

let x = 1e-16_f64;

// for very small x, e^x is approximately 1 + x + x^2 / 2
let approx = x + x * x / 2.0;
let abs_difference = (x.exp_m1() - approx).abs();

assert!(abs_difference < 1e-20);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn ln_1p(self) -> f64[src][−]

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

Examples

let x = 1e-16_f64;

// for very small x, ln(1 + x) is approximately x - x^2 / 2
let approx = x - x * x / 2.0;
let abs_difference = (x.ln_1p() - approx).abs();

assert!(abs_difference < 1e-20);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn sinh(self) -> f64[src][−]

Hyperbolic sine function.

Examples

let e = std::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);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn cosh(self) -> f64[src][−]

Hyperbolic cosine function.

Examples

let e = std::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);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn tanh(self) -> f64[src][−]

Hyperbolic tangent function.

Examples

let e = std::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);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn asinh(self) -> f64[src][−]

Inverse hyperbolic sine function.

Examples

let x = 1.0_f64;
let f = x.sinh().asinh();

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

assert!(abs_difference < 1.0e-10);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn acosh(self) -> f64[src][−]

Inverse hyperbolic cosine function.

Examples

let x = 1.0_f64;
let f = x.cosh().acosh();

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

assert!(abs_difference < 1.0e-10);

Run

#[must_use = "method returns a new number and does not mutate the original value"]

pub fn atanh(self) -> f64[src][−]

Inverse hyperbolic tangent function.

Examples

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

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

assert!(abs_difference < 1.0e-10);

Run

f64 - Rust

impl f64[src]

pub fn sin_cos(self) -> (f64, f64)[src][−]

Recommend

About Joyk

`impl f64`[src]

`pub fn sin_cos(self) -> (f64, f64)`[src][−]