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android / toolchain / rustc / refs/heads/main / . / library / std / src / f64.rs
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//! Constants for the `f64` double-precision floating point type.
//!
//! *[See also the `f64` primitive type](primitive@f64).*
//!
//! Mathematically significant numbers are provided in the `consts` sub-module.
//!
//! For the constants defined directly in this module
//! (as distinct from those defined in the `consts` sub-module),
//! new code should instead use the associated constants
//! defined directly on the `f64` type.
#![stable(feature = "rust1", since = "1.0.0")]
#![allow(missing_docs)]
#[cfg(test)]
mod tests;
#[stable(feature = "rust1", since = "1.0.0")]
#[allow(deprecated, deprecated_in_future)]
pub use core::f64::{
DIGITS, EPSILON, INFINITY, MANTISSA_DIGITS, MAX, MAX_10_EXP, MAX_EXP, MIN, MIN_10_EXP, MIN_EXP,
MIN_POSITIVE, NAN, NEG_INFINITY, RADIX, consts,
};
#[cfg(not(test))]
use crate::intrinsics;
#[cfg(not(test))]
use crate::sys::cmath;
#[cfg(not(test))]
impl f64 {
/// Returns the largest integer less than or equal to `self`.
///
/// This function always returns the precise result.
///
/// # 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);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn floor(self) -> f64 {
unsafe { intrinsics::floorf64(self) }
}
/// Returns the smallest integer greater than or equal to `self`.
///
/// This function always returns the precise result.
///
/// # Examples
///
/// ```
/// let f = 3.01_f64;
/// let g = 4.0_f64;
///
/// assert_eq!(f.ceil(), 4.0);
/// assert_eq!(g.ceil(), 4.0);
/// ```
#[doc(alias = "ceiling")]
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn ceil(self) -> f64 {
unsafe { intrinsics::ceilf64(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.
///
/// # Examples
///
/// ```
/// let f = 3.3_f64;
/// let g = -3.3_f64;
/// let h = -3.7_f64;
/// let i = 3.5_f64;
/// let j = 4.5_f64;
///
/// assert_eq!(f.round(), 3.0);
/// assert_eq!(g.round(), -3.0);
/// assert_eq!(h.round(), -4.0);
/// assert_eq!(i.round(), 4.0);
/// assert_eq!(j.round(), 5.0);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn round(self) -> f64 {
unsafe { intrinsics::roundf64(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.
///
/// # Examples
///
/// ```
/// let f = 3.3_f64;
/// let g = -3.3_f64;
/// let h = 3.5_f64;
/// let i = 4.5_f64;
///
/// assert_eq!(f.round_ties_even(), 3.0);
/// assert_eq!(g.round_ties_even(), -3.0);
/// assert_eq!(h.round_ties_even(), 4.0);
/// assert_eq!(i.round_ties_even(), 4.0);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "round_ties_even", since = "1.77.0")]
#[inline]
pub fn round_ties_even(self) -> f64 {
unsafe { intrinsics::rintf64(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.
///
/// # 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);
/// ```
#[doc(alias = "truncate")]
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn trunc(self) -> f64 {
unsafe { intrinsics::truncf64(self) }
}
/// Returns the fractional part of `self`.
///
/// This function always returns the precise result.
///
/// # 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);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn fract(self) -> f64 {
self - self.trunc()
}
/// Computes the absolute value of `self`.
///
/// This function always returns the precise result.
///
/// # Examples
///
/// ```
/// let x = 3.5_f64;
/// let y = -3.5_f64;
///
/// assert_eq!(x.abs(), x);
/// assert_eq!(y.abs(), -y);
///
/// assert!(f64::NAN.abs().is_nan());
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn abs(self) -> f64 {
unsafe { intrinsics::fabsf64(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
///
/// # 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());
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn signum(self) -> f64 {
if self.is_nan() { Self::NAN } else { 1.0_f64.copysign(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 same payload as `self` and the sign bit of `sign` is
/// returned.
///
/// If `sign` is a NaN, then this operation will still carry over its sign into the result. Note
/// that IEEE 754 doesn't assign any meaning to the sign bit in case of a NaN, and as Rust
/// doesn't guarantee that the bit pattern of NaNs are conserved over arithmetic operations, the
/// result of `copysign` with `sign` being a NaN might produce an unexpected or non-portable
/// result. See the [specification of NaN bit patterns](primitive@f32#nan-bit-patterns) for more
/// info.
///
/// # 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());
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "copysign", since = "1.35.0")]
#[inline]
pub fn copysign(self, sign: f64) -> f64 {
unsafe { intrinsics::copysignf64(self, sign) }
}
/// 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.
///
/// # Precision
///
/// The result of this operation is guaranteed to be the rounded
/// infinite-precision result. It is specified by IEEE 754 as
/// `fusedMultiplyAdd` and guaranteed not to change.
///
/// # Examples
///
/// ```
/// let m = 10.0_f64;
/// let x = 4.0_f64;
/// let b = 60.0_f64;
///
/// assert_eq!(m.mul_add(x, b), 100.0);
/// assert_eq!(m * x + b, 100.0);
///
/// let one_plus_eps = 1.0_f64 + f64::EPSILON;
/// let one_minus_eps = 1.0_f64 - f64::EPSILON;
/// let minus_one = -1.0_f64;
///
/// // The exact result (1 + eps) * (1 - eps) = 1 - eps * eps.
/// assert_eq!(one_plus_eps.mul_add(one_minus_eps, minus_one), -f64::EPSILON * f64::EPSILON);
/// // Different rounding with the non-fused multiply and add.
/// assert_eq!(one_plus_eps * one_minus_eps + minus_one, 0.0);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn mul_add(self, a: f64, b: f64) -> f64 {
unsafe { intrinsics::fmaf64(self, a, b) }
}
/// 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`.
///
/// # Precision
///
/// The result of this operation is guaranteed to be the rounded
/// infinite-precision result.
///
/// # 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
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[inline]
#[stable(feature = "euclidean_division", since = "1.38.0")]
pub fn div_euclid(self, rhs: f64) -> f64 {
let q = (self / rhs).trunc();
if self % rhs < 0.0 {
return if rhs > 0.0 { q - 1.0 } else { q + 1.0 };
}
q
}
/// 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.
///
/// # 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);
/// ```
#[doc(alias = "modulo", alias = "mod")]
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[inline]
#[stable(feature = "euclidean_division", since = "1.38.0")]
pub fn rem_euclid(self, rhs: f64) -> f64 {
let r = self % rhs;
if r < 0.0 { r + rhs.abs() } else { r }
}
/// 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.
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
///
/// # Examples
///
/// ```
/// let x = 2.0_f64;
/// let abs_difference = (x.powi(2) - (x * x)).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn powi(self, n: i32) -> f64 {
unsafe { intrinsics::powif64(self, n) }
}
/// Raises a number to a floating point power.
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
///
/// # Examples
///
/// ```
/// let x = 2.0_f64;
/// let abs_difference = (x.powf(2.0) - (x * x)).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn powf(self, n: f64) -> f64 {
unsafe { intrinsics::powf64(self, n) }
}
/// 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.
///
/// # Examples
///
/// ```
/// let positive = 4.0_f64;
/// let negative = -4.0_f64;
/// let negative_zero = -0.0_f64;
///
/// assert_eq!(positive.sqrt(), 2.0);
/// assert!(negative.sqrt().is_nan());
/// assert!(negative_zero.sqrt() == negative_zero);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn sqrt(self) -> f64 {
unsafe { intrinsics::sqrtf64(self) }
}
/// Returns `e^(self)`, (the exponential function).
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
///
/// # 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);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn exp(self) -> f64 {
unsafe { intrinsics::expf64(self) }
}
/// Returns `2^(self)`.
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
///
/// # Examples
///
/// ```
/// let f = 2.0_f64;
///
/// // 2^2 - 4 == 0
/// let abs_difference = (f.exp2() - 4.0).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn exp2(self) -> f64 {
unsafe { intrinsics::exp2f64(self) }
}
/// Returns the natural logarithm of the number.
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
///
/// # 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);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn ln(self) -> f64 {
unsafe { intrinsics::logf64(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.
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
///
/// # 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);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn log(self, base: f64) -> f64 {
self.ln() / base.ln()
}
/// Returns the base 2 logarithm of the number.
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
///
/// # Examples
///
/// ```
/// let four = 4.0_f64;
///
/// // log2(4) - 2 == 0
/// let abs_difference = (four.log2() - 2.0).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn log2(self) -> f64 {
unsafe { intrinsics::log2f64(self) }
}
/// Returns the base 10 logarithm of the number.
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
///
/// # Examples
///
/// ```
/// let hundred = 100.0_f64;
///
/// // log10(100) - 2 == 0
/// let abs_difference = (hundred.log10() - 2.0).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn log10(self) -> f64 {
unsafe { intrinsics::log10f64(self) }
}
/// The positive difference of two numbers.
///
/// * If `self <= other`: `0.0`
/// * Else: `self - other`
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
/// This function currently corresponds to the `fdim` from libc on Unix and
/// Windows. Note that this might change in the future.
///
/// # 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);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
#[deprecated(
since = "1.10.0",
note = "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)."
)]
pub fn abs_sub(self, other: f64) -> f64 {
unsafe { cmath::fdim(self, other) }
}
/// Returns the cube root of a number.
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
/// This function currently corresponds to the `cbrt` from libc on Unix and
/// Windows. Note that this might change in the future.
///
/// # Examples
///
/// ```
/// let x = 8.0_f64;
///
/// // x^(1/3) - 2 == 0
/// let abs_difference = (x.cbrt() - 2.0).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn cbrt(self) -> f64 {
unsafe { cmath::cbrt(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()`.
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
/// This function currently corresponds to the `hypot` from libc on Unix
/// and Windows. Note that this might change in the future.
///
/// # 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);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn hypot(self, other: f64) -> f64 {
unsafe { cmath::hypot(self, other) }
}
/// Computes the sine of a number (in radians).
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
///
/// # Examples
///
/// ```
/// let x = std::f64::consts::FRAC_PI_2;
///
/// let abs_difference = (x.sin() - 1.0).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn sin(self) -> f64 {
unsafe { intrinsics::sinf64(self) }
}
/// Computes the cosine of a number (in radians).
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
///
/// # Examples
///
/// ```
/// let x = 2.0 * std::f64::consts::PI;
///
/// let abs_difference = (x.cos() - 1.0).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn cos(self) -> f64 {
unsafe { intrinsics::cosf64(self) }
}
/// Computes the tangent of a number (in radians).
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
/// This function currently corresponds to the `tan` from libc on Unix and
/// Windows. Note that this might change in the future.
///
/// # Examples
///
/// ```
/// let x = std::f64::consts::FRAC_PI_4;
/// let abs_difference = (x.tan() - 1.0).abs();
///
/// assert!(abs_difference < 1e-14);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn tan(self) -> f64 {
unsafe { cmath::tan(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].
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
/// This function currently corresponds to the `asin` from libc on Unix and
/// Windows. Note that this might change in the future.
///
/// # 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);
/// ```
#[doc(alias = "arcsin")]
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn asin(self) -> f64 {
unsafe { cmath::asin(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].
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
/// This function currently corresponds to the `acos` from libc on Unix and
/// Windows. Note that this might change in the future.
///
/// # 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);
/// ```
#[doc(alias = "arccos")]
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn acos(self) -> f64 {
unsafe { cmath::acos(self) }
}
/// Computes the arctangent of a number. Return value is in radians in the
/// range [-pi/2, pi/2];
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
/// This function currently corresponds to the `atan` from libc on Unix and
/// Windows. Note that this might change in the future.
///
/// # Examples
///
/// ```
/// let f = 1.0_f64;
///
/// // atan(tan(1))
/// let abs_difference = (f.tan().atan() - 1.0).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
#[doc(alias = "arctan")]
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn atan(self) -> f64 {
unsafe { cmath::atan(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)`
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
/// This function currently corresponds to the `atan2` from libc on Unix
/// and Windows. Note that this might change in the future.
///
/// # 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);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn atan2(self, other: f64) -> f64 {
unsafe { cmath::atan2(self, other) }
}
/// Simultaneously computes the sine and cosine of the number, `x`. Returns
/// `(sin(x), cos(x))`.
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
/// This function currently corresponds to the `(f64::sin(x),
/// f64::cos(x))`. Note that this might change in the future.
///
/// # 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);
/// ```
#[doc(alias = "sincos")]
#[rustc_allow_incoherent_impl]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn sin_cos(self) -> (f64, f64) {
(self.sin(), self.cos())
}
/// Returns `e^(self) - 1` in a way that is accurate even if the
/// number is close to zero.
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
/// This function currently corresponds to the `expm1` from libc on Unix
/// and Windows. Note that this might change in the future.
///
/// # 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);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn exp_m1(self) -> f64 {
unsafe { cmath::expm1(self) }
}
/// Returns `ln(1+n)` (natural logarithm) more accurately than if
/// the operations were performed separately.
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
/// This function currently corresponds to the `log1p` from libc on Unix
/// and Windows. Note that this might change in the future.
///
/// # 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);
/// ```
#[doc(alias = "log1p")]
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn ln_1p(self) -> f64 {
unsafe { cmath::log1p(self) }
}
/// Hyperbolic sine function.
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
/// This function currently corresponds to the `sinh` from libc on Unix
/// and Windows. Note that this might change in the future.
///
/// # 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);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn sinh(self) -> f64 {
unsafe { cmath::sinh(self) }
}
/// Hyperbolic cosine function.
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
/// This function currently corresponds to the `cosh` from libc on Unix
/// and Windows. Note that this might change in the future.
///
/// # 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);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn cosh(self) -> f64 {
unsafe { cmath::cosh(self) }
}
/// Hyperbolic tangent function.
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
/// This function currently corresponds to the `tanh` from libc on Unix
/// and Windows. Note that this might change in the future.
///
/// # 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);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn tanh(self) -> f64 {
unsafe { cmath::tanh(self) }
}
/// Inverse hyperbolic sine function.
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
///
/// # Examples
///
/// ```
/// let x = 1.0_f64;
/// let f = x.sinh().asinh();
///
/// let abs_difference = (f - x).abs();
///
/// assert!(abs_difference < 1.0e-10);
/// ```
#[doc(alias = "arcsinh")]
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn asinh(self) -> f64 {
let ax = self.abs();
let ix = 1.0 / ax;
(ax + (ax / (Self::hypot(1.0, ix) + ix))).ln_1p().copysign(self)
}
/// Inverse hyperbolic cosine function.
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
///
/// # Examples
///
/// ```
/// let x = 1.0_f64;
/// let f = x.cosh().acosh();
///
/// let abs_difference = (f - x).abs();
///
/// assert!(abs_difference < 1.0e-10);
/// ```
#[doc(alias = "arccosh")]
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn acosh(self) -> f64 {
if self < 1.0 {
Self::NAN
} else {
(self + ((self - 1.0).sqrt() * (self + 1.0).sqrt())).ln()
}
}
/// Inverse hyperbolic tangent function.
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
///
/// # Examples
///
/// ```
/// let e = std::f64::consts::E;
/// let f = e.tanh().atanh();
///
/// let abs_difference = (f - e).abs();
///
/// assert!(abs_difference < 1.0e-10);
/// ```
#[doc(alias = "arctanh")]
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn atanh(self) -> f64 {
0.5 * ((2.0 * self) / (1.0 - self)).ln_1p()
}
/// Gamma function.
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
/// This function currently corresponds to the `tgamma` from libc on Unix
/// and Windows. Note that this might change in the future.
///
/// # Examples
///
/// ```
/// #![feature(float_gamma)]
/// let x = 5.0f64;
///
/// let abs_difference = (x.gamma() - 24.0).abs();
///
/// assert!(abs_difference <= f64::EPSILON);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[unstable(feature = "float_gamma", issue = "99842")]
#[inline]
pub fn gamma(self) -> f64 {
unsafe { cmath::tgamma(self) }
}
/// Natural logarithm of the absolute value of the gamma function
///
/// The integer part of the tuple indicates the sign of the gamma function.
///
/// # Unspecified precision
///
/// The precision of this function is non-deterministic. This means it varies by platform, Rust version, and
/// can even differ within the same execution from one invocation to the next.
/// This function currently corresponds to the `lgamma_r` from libc on Unix
/// and Windows. Note that this might change in the future.
///
/// # Examples
///
/// ```
/// #![feature(float_gamma)]
/// let x = 2.0f64;
///
/// let abs_difference = (x.ln_gamma().0 - 0.0).abs();
///
/// assert!(abs_difference <= f64::EPSILON);
/// ```
#[rustc_allow_incoherent_impl]
#[must_use = "method returns a new number and does not mutate the original value"]
#[unstable(feature = "float_gamma", issue = "99842")]
#[inline]
pub fn ln_gamma(self) -> (f64, i32) {
let mut signgamp: i32 = 0;
let x = unsafe { cmath::lgamma_r(self, &mut signgamp) };
(x, signgamp)
}
}