Trait Float

pub trait Float: Sized {
    // Required methods
    fn floor(self) -> Self;
    fn ceil(self) -> Self;
    fn round(self) -> Self;
    fn round_ties_even(self) -> Self;
    fn trunc(self) -> Self;
    fn fract(self) -> Self;
    fn abs(self) -> Self;
    fn signum(self) -> Self;
    fn copysign(self, sign: Self) -> Self;
    fn mul_add(self, a: Self, b: Self) -> Self;
    fn div_euclid(self, rhs: Self) -> Self;
    fn rem_euclid(self, rhs: Self) -> Self;
    fn powi(self, n: i32) -> Self;
    fn powf(self, n: Self) -> Self;
    fn sqrt(self) -> Self;
    fn exp(self) -> Self;
    fn exp2(self) -> Self;
    fn ln(self) -> Self;
    fn log(self, base: Self) -> Self;
    fn log2(self) -> Self;
    fn log10(self) -> Self;
    fn abs_sub(self, other: Self) -> Self;
    fn cbrt(self) -> Self;
    fn hypot(self, other: Self) -> Self;
    fn sin(self) -> Self;
    fn cos(self) -> Self;
    fn tan(self) -> Self;
    fn asin(self) -> Self;
    fn acos(self) -> Self;
    fn atan(self) -> Self;
    fn atan2(self, other: Self) -> Self;
    fn sin_cos(self) -> (Self, Self);
    fn exp_m1(self) -> Self;
    fn ln_1p(self) -> Self;
    fn sinh(self) -> Self;
    fn cosh(self) -> Self;
    fn tanh(self) -> Self;
    fn asinh(self) -> Self;
    fn acosh(self) -> Self;
    fn atanh(self) -> Self;
}

Floating-point math functions

This extension trait defines the missing implementations of floating point math in core present in rust’s std crate.

Required Methods

fn floor(self) -> Self

Returns the largest integer less than or equal to self.

This function always returns the precise result.

fn ceil(self) -> Self

Returns the smallest integer greater than or equal to self.

This function always returns the precise result.

fn round(self) -> Self

Returns the nearest integer to self. If a value is half-way between two integers, round away from 0.0.

This function always returns the precise result.

fn round_ties_even(self) -> Self

Returns the nearest integer to a number. Rounds half-way cases to the number with an even least significant digit.

This function always returns the precise result.

fn trunc(self) -> Self

Returns the integer part of self. This means that non-integer numbers are always truncated towards zero.

This function always returns the precise result.

fn fract(self) -> Self

Returns the fractional part of self.

This function always returns the precise result.

fn abs(self) -> Self

Computes the absolute value of self.

This function always returns the precise result.

fn signum(self) -> Self

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 copysign(self, sign: Self) -> Self

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 bit of sign is returned. Note, however, that conserving the sign bit on NaN across arithmetical operations is not generally guaranteed. See explanation of NaN as a special value for more info.

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

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.

fn div_euclid(self, rhs: Self) -> Self

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.

fn rem_euclid(self, rhs: Self) -> Self

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) approximately.

Precision

The result of this operation is guaranteed to be the rounded infinite-precision result.

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

Raises a number to an integer power.

Using this function is generally faster than using powf. It might have a different sequence of rounding operations than powf, so the results are not guaranteed to agree.

Platform-specific precision

The precision of this function varies by platform and Rust version.

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

Raises a number to a floating point power.

Platform-specific precision

The precision of this function varies by platform and Rust version.

fn sqrt(self) -> Self

Returns the square root of a number.

Returns NaN if self is a negative number other than -0.0.

Precision

The result of this operation is guaranteed to be the rounded infinite-precision result. It is specified by IEEE 754 as squareRoot and guaranteed not to change.

fn exp(self) -> Self

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

Platform-specific precision

The precision of this function varies by platform and Rust version.

fn exp2(self) -> Self

Returns 2^(self).

Platform-specific precision

The precision of this function varies by platform and Rust version.

fn ln(self) -> Self

Returns the natural logarithm of the number.

Platform-specific precision

The precision of this function varies by platform and Rust version.

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

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

The result might 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.

Platform-specific precision

The precision of this function varies by platform and Rust version.

fn log2(self) -> Self

Returns the base 2 logarithm of the number.

Platform-specific precision

The precision of this function varies by platform and Rust version.

fn log10(self) -> Self

Returns the base 10 logarithm of the number.

Platform-specific precision

The precision of this function varies by platform and Rust version.

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

👎Deprecated since 0.2.0: 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.

The positive difference of two numbers.

• If self <= other: 0.0
• Else: self - other

Platform-specific precision

The precision of this function varies by platform and Rust version. This function currently corresponds to the fdim function from libm.

fn cbrt(self) -> Self

Returns the cube root of a number.

Platform-specific precision

The precision of this function varies by platform and Rust version.

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

Compute the distance between the origin and a point (x, y) on the Euclidean plane. Equivalently, compute the length of the hypotenuse of a right-angle triangle with other sides having length x.abs() and y.abs().

Platform-specific precision

The precision of this function varies by platform and Rust version.

fn sin(self) -> Self

Computes the sine of a number (in radians).

Platform-specific precision

The precision of this function varies by platform and Rust version.

fn cos(self) -> Self

Computes the cosine of a number (in radians).

Platform-specific precision

The precision of this function varies by platform and Rust version.

fn tan(self) -> Self

Computes the tangent of a number (in radians).

Platform-specific precision

The precision of this function varies by platform and Rust version.

fn asin(self) -> Self

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].

Platform-specific precision

The precision of this function varies by platform and Rust version.

fn acos(self) -> Self

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].

Platform-specific precision

The precision of this function varies by platform and Rust version.

fn atan(self) -> Self

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

Platform-specific precision

The precision of this function varies by platform and Rust version.

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

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)

Platform-specific precision

The precision of this function varies by platform and Rust version.

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

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

Platform-specific precision

The precision of this function varies by platform and Rust version.

fn exp_m1(self) -> Self

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

Platform-specific precision

The precision of this function varies by platform and Rust version.

fn ln_1p(self) -> Self

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

Platform-specific precision

The precision of this function varies by platform and Rust version.

fn sinh(self) -> Self

Hyperbolic sine function.

Platform-specific precision

The precision of this function varies by platform and Rust version.

fn cosh(self) -> Self

Hyperbolic cosine function.

Platform-specific precision

The precision of this function varies by platform and Rust version.

fn tanh(self) -> Self

Hyperbolic tangent function.

Platform-specific precision

The precision of this function varies by platform and Rust version.

fn asinh(self) -> Self

Inverse hyperbolic sine function.

Platform-specific precision

The precision of this function varies by platform and Rust version.

fn acosh(self) -> Self

Inverse hyperbolic cosine function.

Platform-specific precision

The precision of this function varies by platform and Rust version.

fn atanh(self) -> Self

Inverse hyperbolic tangent function.

Platform-specific precision

The precision of this function varies by platform and Rust version.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl Float for f32

fn floor(self) -> Self

fn ceil(self) -> Self

fn round(self) -> Self

fn round_ties_even(self) -> Self

fn trunc(self) -> Self

fn fract(self) -> Self

fn abs(self) -> Self

fn signum(self) -> Self

fn copysign(self, sign: Self) -> Self

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

fn div_euclid(self, rhs: Self) -> Self

fn rem_euclid(self, rhs: Self) -> Self

fn powi(self, exp: i32) -> Self

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

fn sqrt(self) -> Self

fn exp(self) -> Self

fn exp2(self) -> Self

fn ln(self) -> Self

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

fn log2(self) -> Self

fn log10(self) -> Self

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

👎Deprecated since 0.2.0: 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.

fn cbrt(self) -> Self

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

fn sin(self) -> Self

fn cos(self) -> Self

fn tan(self) -> Self

fn asin(self) -> Self

fn acos(self) -> Self

fn atan(self) -> Self

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

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

fn exp_m1(self) -> Self

fn ln_1p(self) -> Self

fn sinh(self) -> Self

fn cosh(self) -> Self

fn tanh(self) -> Self

fn asinh(self) -> Self

fn acosh(self) -> Self

fn atanh(self) -> Self

impl Float for f64

fn floor(self) -> Self

fn ceil(self) -> Self

fn round(self) -> Self

fn round_ties_even(self) -> Self

fn trunc(self) -> Self

fn fract(self) -> Self

fn abs(self) -> Self

fn signum(self) -> Self

fn copysign(self, sign: Self) -> Self

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

fn div_euclid(self, rhs: Self) -> Self

fn rem_euclid(self, rhs: Self) -> Self

fn powi(self, exp: i32) -> Self

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

fn sqrt(self) -> Self

fn exp(self) -> Self

fn exp2(self) -> Self

fn ln(self) -> Self

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

fn log2(self) -> Self

fn log10(self) -> Self

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

👎Deprecated since 0.2.0: 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.

fn cbrt(self) -> Self

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

fn sin(self) -> Self

fn cos(self) -> Self

fn tan(self) -> Self

fn asin(self) -> Self

fn acos(self) -> Self

fn atan(self) -> Self

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

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

fn exp_m1(self) -> Self

fn ln_1p(self) -> Self

fn sinh(self) -> Self

fn cosh(self) -> Self

fn tanh(self) -> Self

fn asinh(self) -> Self

fn acosh(self) -> Self

fn atanh(self) -> Self

Implementors