1 // Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! This module provides constants which are specific to the implementation
12 //! of the `f32` floating point data type. Mathematically significant
13 //! numbers are provided in the `consts` sub-module.
15 //! *[See also the `f32` primitive type](../primitive.f32.html).*
17 #![stable(feature = "rust1", since = "1.0.0")]
18 #![allow(missing_docs)]
28 #[stable(feature = "rust1", since = "1.0.0")]
29 pub use core::f32::{RADIX, MANTISSA_DIGITS, DIGITS, EPSILON};
30 #[stable(feature = "rust1", since = "1.0.0")]
31 pub use core::f32::{MIN_EXP, MAX_EXP, MIN_10_EXP};
32 #[stable(feature = "rust1", since = "1.0.0")]
33 pub use core::f32::{MAX_10_EXP, NAN, INFINITY, NEG_INFINITY};
34 #[stable(feature = "rust1", since = "1.0.0")]
35 pub use core::f32::{MIN, MIN_POSITIVE, MAX};
36 #[stable(feature = "rust1", since = "1.0.0")]
37 pub use core::f32::consts;
41 use libc::{c_float, c_int};
44 pub fn cbrtf(n: c_float) -> c_float;
45 pub fn erff(n: c_float) -> c_float;
46 pub fn erfcf(n: c_float) -> c_float;
47 pub fn expm1f(n: c_float) -> c_float;
48 pub fn fdimf(a: c_float, b: c_float) -> c_float;
49 pub fn fmaxf(a: c_float, b: c_float) -> c_float;
50 pub fn fminf(a: c_float, b: c_float) -> c_float;
51 pub fn fmodf(a: c_float, b: c_float) -> c_float;
52 pub fn ilogbf(n: c_float) -> c_int;
53 pub fn logbf(n: c_float) -> c_float;
54 pub fn log1pf(n: c_float) -> c_float;
55 pub fn modff(n: c_float, iptr: &mut c_float) -> c_float;
56 pub fn nextafterf(x: c_float, y: c_float) -> c_float;
57 pub fn tgammaf(n: c_float) -> c_float;
59 #[cfg_attr(all(windows, target_env = "msvc"), link_name = "__lgammaf_r")]
60 pub fn lgammaf_r(n: c_float, sign: &mut c_int) -> c_float;
61 #[cfg_attr(all(windows, target_env = "msvc"), link_name = "_hypotf")]
62 pub fn hypotf(x: c_float, y: c_float) -> c_float;
65 // See the comments in the `floor` function for why MSVC is special
67 #[cfg(not(target_env = "msvc"))]
69 pub fn acosf(n: c_float) -> c_float;
70 pub fn asinf(n: c_float) -> c_float;
71 pub fn atan2f(a: c_float, b: c_float) -> c_float;
72 pub fn atanf(n: c_float) -> c_float;
73 pub fn coshf(n: c_float) -> c_float;
74 pub fn sinhf(n: c_float) -> c_float;
75 pub fn tanf(n: c_float) -> c_float;
76 pub fn tanhf(n: c_float) -> c_float;
79 #[cfg(target_env = "msvc")]
80 pub use self::shims::*;
81 #[cfg(target_env = "msvc")]
86 pub unsafe fn acosf(n: c_float) -> c_float {
87 f64::acos(n as f64) as c_float
91 pub unsafe fn asinf(n: c_float) -> c_float {
92 f64::asin(n as f64) as c_float
96 pub unsafe fn atan2f(n: c_float, b: c_float) -> c_float {
97 f64::atan2(n as f64, b as f64) as c_float
101 pub unsafe fn atanf(n: c_float) -> c_float {
102 f64::atan(n as f64) as c_float
106 pub unsafe fn coshf(n: c_float) -> c_float {
107 f64::cosh(n as f64) as c_float
111 pub unsafe fn sinhf(n: c_float) -> c_float {
112 f64::sinh(n as f64) as c_float
116 pub unsafe fn tanf(n: c_float) -> c_float {
117 f64::tan(n as f64) as c_float
121 pub unsafe fn tanhf(n: c_float) -> c_float {
122 f64::tanh(n as f64) as c_float
130 /// Returns `true` if this value is `NaN` and false otherwise.
135 /// let nan = f32::NAN;
138 /// assert!(nan.is_nan());
139 /// assert!(!f.is_nan());
141 #[stable(feature = "rust1", since = "1.0.0")]
143 pub fn is_nan(self) -> bool { num::Float::is_nan(self) }
145 /// Returns `true` if this value is positive infinity or negative infinity and
152 /// let inf = f32::INFINITY;
153 /// let neg_inf = f32::NEG_INFINITY;
154 /// let nan = f32::NAN;
156 /// assert!(!f.is_infinite());
157 /// assert!(!nan.is_infinite());
159 /// assert!(inf.is_infinite());
160 /// assert!(neg_inf.is_infinite());
162 #[stable(feature = "rust1", since = "1.0.0")]
164 pub fn is_infinite(self) -> bool { num::Float::is_infinite(self) }
166 /// Returns `true` if this number is neither infinite nor `NaN`.
172 /// let inf = f32::INFINITY;
173 /// let neg_inf = f32::NEG_INFINITY;
174 /// let nan = f32::NAN;
176 /// assert!(f.is_finite());
178 /// assert!(!nan.is_finite());
179 /// assert!(!inf.is_finite());
180 /// assert!(!neg_inf.is_finite());
182 #[stable(feature = "rust1", since = "1.0.0")]
184 pub fn is_finite(self) -> bool { num::Float::is_finite(self) }
186 /// Returns `true` if the number is neither zero, infinite,
187 /// [subnormal][subnormal], or `NaN`.
192 /// let min = f32::MIN_POSITIVE; // 1.17549435e-38f32
193 /// let max = f32::MAX;
194 /// let lower_than_min = 1.0e-40_f32;
195 /// let zero = 0.0_f32;
197 /// assert!(min.is_normal());
198 /// assert!(max.is_normal());
200 /// assert!(!zero.is_normal());
201 /// assert!(!f32::NAN.is_normal());
202 /// assert!(!f32::INFINITY.is_normal());
203 /// // Values between `0` and `min` are Subnormal.
204 /// assert!(!lower_than_min.is_normal());
206 /// [subnormal]: https://en.wikipedia.org/wiki/Denormal_number
207 #[stable(feature = "rust1", since = "1.0.0")]
209 pub fn is_normal(self) -> bool { num::Float::is_normal(self) }
211 /// Returns the floating point category of the number. If only one property
212 /// is going to be tested, it is generally faster to use the specific
213 /// predicate instead.
216 /// use std::num::FpCategory;
219 /// let num = 12.4_f32;
220 /// let inf = f32::INFINITY;
222 /// assert_eq!(num.classify(), FpCategory::Normal);
223 /// assert_eq!(inf.classify(), FpCategory::Infinite);
225 #[stable(feature = "rust1", since = "1.0.0")]
227 pub fn classify(self) -> FpCategory { num::Float::classify(self) }
229 /// Returns the largest integer less than or equal to a number.
232 /// let f = 3.99_f32;
235 /// assert_eq!(f.floor(), 3.0);
236 /// assert_eq!(g.floor(), 3.0);
238 #[stable(feature = "rust1", since = "1.0.0")]
240 pub fn floor(self) -> f32 {
241 // On MSVC LLVM will lower many math intrinsics to a call to the
242 // corresponding function. On MSVC, however, many of these functions
243 // aren't actually available as symbols to call, but rather they are all
244 // `static inline` functions in header files. This means that from a C
245 // perspective it's "compatible", but not so much from an ABI
246 // perspective (which we're worried about).
248 // The inline header functions always just cast to a f64 and do their
249 // operation, so we do that here as well, but only for MSVC targets.
251 // Note that there are many MSVC-specific float operations which
252 // redirect to this comment, so `floorf` is just one case of a missing
253 // function on MSVC, but there are many others elsewhere.
254 #[cfg(target_env = "msvc")]
255 return (self as f64).floor() as f32;
256 #[cfg(not(target_env = "msvc"))]
257 return unsafe { intrinsics::floorf32(self) };
260 /// Returns the smallest integer greater than or equal to a number.
263 /// let f = 3.01_f32;
266 /// assert_eq!(f.ceil(), 4.0);
267 /// assert_eq!(g.ceil(), 4.0);
269 #[stable(feature = "rust1", since = "1.0.0")]
271 pub fn ceil(self) -> f32 {
272 // see notes above in `floor`
273 #[cfg(target_env = "msvc")]
274 return (self as f64).ceil() as f32;
275 #[cfg(not(target_env = "msvc"))]
276 return unsafe { intrinsics::ceilf32(self) };
279 /// Returns the nearest integer to a number. Round half-way cases away from
284 /// let g = -3.3_f32;
286 /// assert_eq!(f.round(), 3.0);
287 /// assert_eq!(g.round(), -3.0);
289 #[stable(feature = "rust1", since = "1.0.0")]
291 pub fn round(self) -> f32 {
292 unsafe { intrinsics::roundf32(self) }
295 /// Returns the integer part of a number.
299 /// let g = -3.7_f32;
301 /// assert_eq!(f.trunc(), 3.0);
302 /// assert_eq!(g.trunc(), -3.0);
304 #[stable(feature = "rust1", since = "1.0.0")]
306 pub fn trunc(self) -> f32 {
307 unsafe { intrinsics::truncf32(self) }
310 /// Returns the fractional part of a number.
316 /// let y = -3.5_f32;
317 /// let abs_difference_x = (x.fract() - 0.5).abs();
318 /// let abs_difference_y = (y.fract() - (-0.5)).abs();
320 /// assert!(abs_difference_x <= f32::EPSILON);
321 /// assert!(abs_difference_y <= f32::EPSILON);
323 #[stable(feature = "rust1", since = "1.0.0")]
325 pub fn fract(self) -> f32 { self - self.trunc() }
327 /// Computes the absolute value of `self`. Returns `NAN` if the
334 /// let y = -3.5_f32;
336 /// let abs_difference_x = (x.abs() - x).abs();
337 /// let abs_difference_y = (y.abs() - (-y)).abs();
339 /// assert!(abs_difference_x <= f32::EPSILON);
340 /// assert!(abs_difference_y <= f32::EPSILON);
342 /// assert!(f32::NAN.abs().is_nan());
344 #[stable(feature = "rust1", since = "1.0.0")]
346 pub fn abs(self) -> f32 { num::Float::abs(self) }
348 /// Returns a number that represents the sign of `self`.
350 /// - `1.0` if the number is positive, `+0.0` or `INFINITY`
351 /// - `-1.0` if the number is negative, `-0.0` or `NEG_INFINITY`
352 /// - `NAN` if the number is `NAN`
359 /// assert_eq!(f.signum(), 1.0);
360 /// assert_eq!(f32::NEG_INFINITY.signum(), -1.0);
362 /// assert!(f32::NAN.signum().is_nan());
364 #[stable(feature = "rust1", since = "1.0.0")]
366 pub fn signum(self) -> f32 { num::Float::signum(self) }
368 /// Returns `true` if `self`'s sign bit is positive, including
369 /// `+0.0` and `INFINITY`.
374 /// let nan = f32::NAN;
376 /// let g = -7.0_f32;
378 /// assert!(f.is_sign_positive());
379 /// assert!(!g.is_sign_positive());
380 /// // Requires both tests to determine if is `NaN`
381 /// assert!(!nan.is_sign_positive() && !nan.is_sign_negative());
383 #[stable(feature = "rust1", since = "1.0.0")]
385 pub fn is_sign_positive(self) -> bool { num::Float::is_sign_positive(self) }
387 /// Returns `true` if `self`'s sign is negative, including `-0.0`
388 /// and `NEG_INFINITY`.
393 /// let nan = f32::NAN;
397 /// assert!(!f.is_sign_negative());
398 /// assert!(g.is_sign_negative());
399 /// // Requires both tests to determine if is `NaN`.
400 /// assert!(!nan.is_sign_positive() && !nan.is_sign_negative());
402 #[stable(feature = "rust1", since = "1.0.0")]
404 pub fn is_sign_negative(self) -> bool { num::Float::is_sign_negative(self) }
406 /// Fused multiply-add. Computes `(self * a) + b` with only one rounding
407 /// error. This produces a more accurate result with better performance than
408 /// a separate multiplication operation followed by an add.
413 /// let m = 10.0_f32;
415 /// let b = 60.0_f32;
418 /// let abs_difference = (m.mul_add(x, b) - (m*x + b)).abs();
420 /// assert!(abs_difference <= f32::EPSILON);
422 #[stable(feature = "rust1", since = "1.0.0")]
424 pub fn mul_add(self, a: f32, b: f32) -> f32 {
425 unsafe { intrinsics::fmaf32(self, a, b) }
428 /// Takes the reciprocal (inverse) of a number, `1/x`.
434 /// let abs_difference = (x.recip() - (1.0/x)).abs();
436 /// assert!(abs_difference <= f32::EPSILON);
438 #[stable(feature = "rust1", since = "1.0.0")]
440 pub fn recip(self) -> f32 { num::Float::recip(self) }
442 /// Raises a number to an integer power.
444 /// Using this function is generally faster than using `powf`
450 /// let abs_difference = (x.powi(2) - x*x).abs();
452 /// assert!(abs_difference <= f32::EPSILON);
454 #[stable(feature = "rust1", since = "1.0.0")]
456 pub fn powi(self, n: i32) -> f32 { num::Float::powi(self, n) }
458 /// Raises a number to a floating point power.
464 /// let abs_difference = (x.powf(2.0) - x*x).abs();
466 /// assert!(abs_difference <= f32::EPSILON);
468 #[stable(feature = "rust1", since = "1.0.0")]
470 pub fn powf(self, n: f32) -> f32 {
471 // see notes above in `floor`
472 #[cfg(target_env = "msvc")]
473 return (self as f64).powf(n as f64) as f32;
474 #[cfg(not(target_env = "msvc"))]
475 return unsafe { intrinsics::powf32(self, n) };
478 /// Takes the square root of a number.
480 /// Returns NaN if `self` is a negative number.
485 /// let positive = 4.0_f32;
486 /// let negative = -4.0_f32;
488 /// let abs_difference = (positive.sqrt() - 2.0).abs();
490 /// assert!(abs_difference <= f32::EPSILON);
491 /// assert!(negative.sqrt().is_nan());
493 #[stable(feature = "rust1", since = "1.0.0")]
495 pub fn sqrt(self) -> f32 {
499 unsafe { intrinsics::sqrtf32(self) }
503 /// Returns `e^(self)`, (the exponential function).
508 /// let one = 1.0f32;
510 /// let e = one.exp();
512 /// // ln(e) - 1 == 0
513 /// let abs_difference = (e.ln() - 1.0).abs();
515 /// assert!(abs_difference <= f32::EPSILON);
517 #[stable(feature = "rust1", since = "1.0.0")]
519 pub fn exp(self) -> f32 {
520 // see notes above in `floor`
521 #[cfg(target_env = "msvc")]
522 return (self as f64).exp() as f32;
523 #[cfg(not(target_env = "msvc"))]
524 return unsafe { intrinsics::expf32(self) };
527 /// Returns `2^(self)`.
535 /// let abs_difference = (f.exp2() - 4.0).abs();
537 /// assert!(abs_difference <= f32::EPSILON);
539 #[stable(feature = "rust1", since = "1.0.0")]
541 pub fn exp2(self) -> f32 {
542 unsafe { intrinsics::exp2f32(self) }
545 /// Returns the natural logarithm of the number.
550 /// let one = 1.0f32;
552 /// let e = one.exp();
554 /// // ln(e) - 1 == 0
555 /// let abs_difference = (e.ln() - 1.0).abs();
557 /// assert!(abs_difference <= f32::EPSILON);
559 #[stable(feature = "rust1", since = "1.0.0")]
561 pub fn ln(self) -> f32 {
562 // see notes above in `floor`
563 #[cfg(target_env = "msvc")]
564 return (self as f64).ln() as f32;
565 #[cfg(not(target_env = "msvc"))]
566 return unsafe { intrinsics::logf32(self) };
569 /// Returns the logarithm of the number with respect to an arbitrary base.
574 /// let ten = 10.0f32;
575 /// let two = 2.0f32;
577 /// // log10(10) - 1 == 0
578 /// let abs_difference_10 = (ten.log(10.0) - 1.0).abs();
580 /// // log2(2) - 1 == 0
581 /// let abs_difference_2 = (two.log(2.0) - 1.0).abs();
583 /// assert!(abs_difference_10 <= f32::EPSILON);
584 /// assert!(abs_difference_2 <= f32::EPSILON);
586 #[stable(feature = "rust1", since = "1.0.0")]
588 pub fn log(self, base: f32) -> f32 { self.ln() / base.ln() }
590 /// Returns the base 2 logarithm of the number.
595 /// let two = 2.0f32;
597 /// // log2(2) - 1 == 0
598 /// let abs_difference = (two.log2() - 1.0).abs();
600 /// assert!(abs_difference <= f32::EPSILON);
602 #[stable(feature = "rust1", since = "1.0.0")]
604 pub fn log2(self) -> f32 {
605 #[cfg(target_os = "android")]
606 return ::sys::android::log2f32(self);
607 #[cfg(not(target_os = "android"))]
608 return unsafe { intrinsics::log2f32(self) };
611 /// Returns the base 10 logarithm of the number.
616 /// let ten = 10.0f32;
618 /// // log10(10) - 1 == 0
619 /// let abs_difference = (ten.log10() - 1.0).abs();
621 /// assert!(abs_difference <= f32::EPSILON);
623 #[stable(feature = "rust1", since = "1.0.0")]
625 pub fn log10(self) -> f32 {
626 // see notes above in `floor`
627 #[cfg(target_env = "msvc")]
628 return (self as f64).log10() as f32;
629 #[cfg(not(target_env = "msvc"))]
630 return unsafe { intrinsics::log10f32(self) };
633 /// Converts radians to degrees.
636 /// use std::f32::{self, consts};
638 /// let angle = consts::PI;
640 /// let abs_difference = (angle.to_degrees() - 180.0).abs();
642 /// assert!(abs_difference <= f32::EPSILON);
644 #[stable(feature = "f32_deg_rad_conversions", since="1.7.0")]
646 pub fn to_degrees(self) -> f32 { num::Float::to_degrees(self) }
648 /// Converts degrees to radians.
651 /// use std::f32::{self, consts};
653 /// let angle = 180.0f32;
655 /// let abs_difference = (angle.to_radians() - consts::PI).abs();
657 /// assert!(abs_difference <= f32::EPSILON);
659 #[stable(feature = "f32_deg_rad_conversions", since="1.7.0")]
661 pub fn to_radians(self) -> f32 { num::Float::to_radians(self) }
663 /// Returns the maximum of the two numbers.
669 /// assert_eq!(x.max(y), y);
672 /// If one of the arguments is NaN, then the other argument is returned.
673 #[stable(feature = "rust1", since = "1.0.0")]
675 pub fn max(self, other: f32) -> f32 {
676 unsafe { cmath::fmaxf(self, other) }
679 /// Returns the minimum of the two numbers.
685 /// assert_eq!(x.min(y), x);
688 /// If one of the arguments is NaN, then the other argument is returned.
689 #[stable(feature = "rust1", since = "1.0.0")]
691 pub fn min(self, other: f32) -> f32 {
692 unsafe { cmath::fminf(self, other) }
695 /// The positive difference of two numbers.
697 /// * If `self <= other`: `0:0`
698 /// * Else: `self - other`
706 /// let abs_difference_x = (x.abs_sub(1.0) - 2.0).abs();
707 /// let abs_difference_y = (y.abs_sub(1.0) - 0.0).abs();
709 /// assert!(abs_difference_x <= f32::EPSILON);
710 /// assert!(abs_difference_y <= f32::EPSILON);
712 #[stable(feature = "rust1", since = "1.0.0")]
714 #[rustc_deprecated(since = "1.10.0",
715 reason = "you probably meant `(self - other).abs()`: \
716 this operation is `(self - other).max(0.0)` (also \
717 known as `fdimf` in C). If you truly need the positive \
718 difference, consider using that expression or the C function \
719 `fdimf`, depending on how you wish to handle NaN (please consider \
720 filing an issue describing your use-case too).")]
721 pub fn abs_sub(self, other: f32) -> f32 {
722 unsafe { cmath::fdimf(self, other) }
725 /// Takes the cubic root of a number.
732 /// // x^(1/3) - 2 == 0
733 /// let abs_difference = (x.cbrt() - 2.0).abs();
735 /// assert!(abs_difference <= f32::EPSILON);
737 #[stable(feature = "rust1", since = "1.0.0")]
739 pub fn cbrt(self) -> f32 {
740 unsafe { cmath::cbrtf(self) }
743 /// Calculates the length of the hypotenuse of a right-angle triangle given
744 /// legs of length `x` and `y`.
752 /// // sqrt(x^2 + y^2)
753 /// let abs_difference = (x.hypot(y) - (x.powi(2) + y.powi(2)).sqrt()).abs();
755 /// assert!(abs_difference <= f32::EPSILON);
757 #[stable(feature = "rust1", since = "1.0.0")]
759 pub fn hypot(self, other: f32) -> f32 {
760 unsafe { cmath::hypotf(self, other) }
763 /// Computes the sine of a number (in radians).
768 /// let x = f32::consts::PI/2.0;
770 /// let abs_difference = (x.sin() - 1.0).abs();
772 /// assert!(abs_difference <= f32::EPSILON);
774 #[stable(feature = "rust1", since = "1.0.0")]
776 pub fn sin(self) -> f32 {
777 // see notes in `core::f32::Float::floor`
778 #[cfg(target_env = "msvc")]
779 return (self as f64).sin() as f32;
780 #[cfg(not(target_env = "msvc"))]
781 return unsafe { intrinsics::sinf32(self) };
784 /// Computes the cosine of a number (in radians).
789 /// let x = 2.0*f32::consts::PI;
791 /// let abs_difference = (x.cos() - 1.0).abs();
793 /// assert!(abs_difference <= f32::EPSILON);
795 #[stable(feature = "rust1", since = "1.0.0")]
797 pub fn cos(self) -> f32 {
798 // see notes in `core::f32::Float::floor`
799 #[cfg(target_env = "msvc")]
800 return (self as f64).cos() as f32;
801 #[cfg(not(target_env = "msvc"))]
802 return unsafe { intrinsics::cosf32(self) };
805 /// Computes the tangent of a number (in radians).
810 /// let x = f32::consts::PI / 4.0;
811 /// let abs_difference = (x.tan() - 1.0).abs();
813 /// assert!(abs_difference <= f32::EPSILON);
815 #[stable(feature = "rust1", since = "1.0.0")]
817 pub fn tan(self) -> f32 {
818 unsafe { cmath::tanf(self) }
821 /// Computes the arcsine of a number. Return value is in radians in
822 /// the range [-pi/2, pi/2] or NaN if the number is outside the range
828 /// let f = f32::consts::PI / 2.0;
830 /// // asin(sin(pi/2))
831 /// let abs_difference = (f.sin().asin() - f32::consts::PI / 2.0).abs();
833 /// assert!(abs_difference <= f32::EPSILON);
835 #[stable(feature = "rust1", since = "1.0.0")]
837 pub fn asin(self) -> f32 {
838 unsafe { cmath::asinf(self) }
841 /// Computes the arccosine of a number. Return value is in radians in
842 /// the range [0, pi] or NaN if the number is outside the range
848 /// let f = f32::consts::PI / 4.0;
850 /// // acos(cos(pi/4))
851 /// let abs_difference = (f.cos().acos() - f32::consts::PI / 4.0).abs();
853 /// assert!(abs_difference <= f32::EPSILON);
855 #[stable(feature = "rust1", since = "1.0.0")]
857 pub fn acos(self) -> f32 {
858 unsafe { cmath::acosf(self) }
861 /// Computes the arctangent of a number. Return value is in radians in the
862 /// range [-pi/2, pi/2];
870 /// let abs_difference = (f.tan().atan() - 1.0).abs();
872 /// assert!(abs_difference <= f32::EPSILON);
874 #[stable(feature = "rust1", since = "1.0.0")]
876 pub fn atan(self) -> f32 {
877 unsafe { cmath::atanf(self) }
880 /// Computes the four quadrant arctangent of `self` (`y`) and `other` (`x`).
882 /// * `x = 0`, `y = 0`: `0`
883 /// * `x >= 0`: `arctan(y/x)` -> `[-pi/2, pi/2]`
884 /// * `y >= 0`: `arctan(y/x) + pi` -> `(pi/2, pi]`
885 /// * `y < 0`: `arctan(y/x) - pi` -> `(-pi, -pi/2)`
890 /// let pi = f32::consts::PI;
891 /// // All angles from horizontal right (+x)
892 /// // 45 deg counter-clockwise
894 /// let y1 = -3.0f32;
896 /// // 135 deg clockwise
897 /// let x2 = -3.0f32;
900 /// let abs_difference_1 = (y1.atan2(x1) - (-pi/4.0)).abs();
901 /// let abs_difference_2 = (y2.atan2(x2) - 3.0*pi/4.0).abs();
903 /// assert!(abs_difference_1 <= f32::EPSILON);
904 /// assert!(abs_difference_2 <= f32::EPSILON);
906 #[stable(feature = "rust1", since = "1.0.0")]
908 pub fn atan2(self, other: f32) -> f32 {
909 unsafe { cmath::atan2f(self, other) }
912 /// Simultaneously computes the sine and cosine of the number, `x`. Returns
913 /// `(sin(x), cos(x))`.
918 /// let x = f32::consts::PI/4.0;
919 /// let f = x.sin_cos();
921 /// let abs_difference_0 = (f.0 - x.sin()).abs();
922 /// let abs_difference_1 = (f.1 - x.cos()).abs();
924 /// assert!(abs_difference_0 <= f32::EPSILON);
925 /// assert!(abs_difference_1 <= f32::EPSILON);
927 #[stable(feature = "rust1", since = "1.0.0")]
929 pub fn sin_cos(self) -> (f32, f32) {
930 (self.sin(), self.cos())
933 /// Returns `e^(self) - 1` in a way that is accurate even if the
934 /// number is close to zero.
942 /// let abs_difference = (x.ln().exp_m1() - 5.0).abs();
944 /// assert!(abs_difference <= f32::EPSILON);
946 #[stable(feature = "rust1", since = "1.0.0")]
948 pub fn exp_m1(self) -> f32 {
949 unsafe { cmath::expm1f(self) }
952 /// Returns `ln(1+n)` (natural logarithm) more accurately than if
953 /// the operations were performed separately.
958 /// let x = f32::consts::E - 1.0;
960 /// // ln(1 + (e - 1)) == ln(e) == 1
961 /// let abs_difference = (x.ln_1p() - 1.0).abs();
963 /// assert!(abs_difference <= f32::EPSILON);
965 #[stable(feature = "rust1", since = "1.0.0")]
967 pub fn ln_1p(self) -> f32 {
968 unsafe { cmath::log1pf(self) }
971 /// Hyperbolic sine function.
976 /// let e = f32::consts::E;
979 /// let f = x.sinh();
980 /// // Solving sinh() at 1 gives `(e^2-1)/(2e)`
981 /// let g = (e*e - 1.0)/(2.0*e);
982 /// let abs_difference = (f - g).abs();
984 /// assert!(abs_difference <= f32::EPSILON);
986 #[stable(feature = "rust1", since = "1.0.0")]
988 pub fn sinh(self) -> f32 {
989 unsafe { cmath::sinhf(self) }
992 /// Hyperbolic cosine function.
997 /// let e = f32::consts::E;
999 /// let f = x.cosh();
1000 /// // Solving cosh() at 1 gives this result
1001 /// let g = (e*e + 1.0)/(2.0*e);
1002 /// let abs_difference = (f - g).abs();
1005 /// assert!(abs_difference <= f32::EPSILON);
1007 #[stable(feature = "rust1", since = "1.0.0")]
1009 pub fn cosh(self) -> f32 {
1010 unsafe { cmath::coshf(self) }
1013 /// Hyperbolic tangent function.
1018 /// let e = f32::consts::E;
1021 /// let f = x.tanh();
1022 /// // Solving tanh() at 1 gives `(1 - e^(-2))/(1 + e^(-2))`
1023 /// let g = (1.0 - e.powi(-2))/(1.0 + e.powi(-2));
1024 /// let abs_difference = (f - g).abs();
1026 /// assert!(abs_difference <= f32::EPSILON);
1028 #[stable(feature = "rust1", since = "1.0.0")]
1030 pub fn tanh(self) -> f32 {
1031 unsafe { cmath::tanhf(self) }
1034 /// Inverse hyperbolic sine function.
1040 /// let f = x.sinh().asinh();
1042 /// let abs_difference = (f - x).abs();
1044 /// assert!(abs_difference <= f32::EPSILON);
1046 #[stable(feature = "rust1", since = "1.0.0")]
1048 pub fn asinh(self) -> f32 {
1049 if self == NEG_INFINITY {
1052 (self + ((self * self) + 1.0).sqrt()).ln()
1056 /// Inverse hyperbolic cosine function.
1062 /// let f = x.cosh().acosh();
1064 /// let abs_difference = (f - x).abs();
1066 /// assert!(abs_difference <= f32::EPSILON);
1068 #[stable(feature = "rust1", since = "1.0.0")]
1070 pub fn acosh(self) -> f32 {
1072 x if x < 1.0 => ::f32::NAN,
1073 x => (x + ((x * x) - 1.0).sqrt()).ln(),
1077 /// Inverse hyperbolic tangent function.
1082 /// let e = f32::consts::E;
1083 /// let f = e.tanh().atanh();
1085 /// let abs_difference = (f - e).abs();
1087 /// assert!(abs_difference <= 1e-5);
1089 #[stable(feature = "rust1", since = "1.0.0")]
1091 pub fn atanh(self) -> f32 {
1092 0.5 * ((2.0 * self) / (1.0 - self)).ln_1p()
1095 /// Raw transmutation to `u32`.
1097 /// Converts the `f32` into its raw memory representation,
1098 /// similar to the `transmute` function.
1100 /// Note that this function is distinct from casting.
1105 /// #![feature(float_bits_conv)]
1106 /// assert_ne!((1f32).to_bits(), 1f32 as u32); // to_bits() is not casting!
1107 /// assert_eq!((12.5f32).to_bits(), 0x41480000);
1110 #[unstable(feature = "float_bits_conv", reason = "recently added", issue = "40470")]
1112 pub fn to_bits(self) -> u32 {
1113 unsafe { ::mem::transmute(self) }
1116 /// Raw transmutation from `u32`.
1118 /// Converts the given `u32` containing the float's raw memory
1119 /// representation into the `f32` type, similar to the
1120 /// `transmute` function.
1122 /// There is only one difference to a bare `transmute`:
1123 /// Due to the implications onto Rust's safety promises being
1124 /// uncertain, if the representation of a signaling NaN "sNaN" float
1125 /// is passed to the function, the implementation is allowed to
1126 /// return a quiet NaN instead.
1128 /// Note that this function is distinct from casting.
1133 /// #![feature(float_bits_conv)]
1135 /// let v = f32::from_bits(0x41480000);
1136 /// let difference = (v - 12.5).abs();
1137 /// assert!(difference <= 1e-5);
1138 /// // Example for a signaling NaN value:
1139 /// let snan = 0x7F800001;
1140 /// assert_ne!(f32::from_bits(snan).to_bits(), snan);
1142 #[unstable(feature = "float_bits_conv", reason = "recently added", issue = "40470")]
1144 pub fn from_bits(mut v: u32) -> Self {
1145 const EXP_MASK: u32 = 0x7F800000;
1146 const QNAN_MASK: u32 = 0x00400000;
1147 const FRACT_MASK: u32 = 0x007FFFFF;
1148 if v & EXP_MASK == EXP_MASK && v & FRACT_MASK != 0 {
1149 // If we have a NaN value, we
1150 // convert signaling NaN values to quiet NaN
1151 // by setting the the highest bit of the fraction
1154 unsafe { ::mem::transmute(v) }
1163 use num::FpCategory as Fp;
1167 test_num(10f32, 2f32);
1172 assert_eq!(NAN.min(2.0), 2.0);
1173 assert_eq!(2.0f32.min(NAN), 2.0);
1178 assert_eq!(NAN.max(2.0), 2.0);
1179 assert_eq!(2.0f32.max(NAN), 2.0);
1184 let nan: f32 = f32::NAN;
1185 assert!(nan.is_nan());
1186 assert!(!nan.is_infinite());
1187 assert!(!nan.is_finite());
1188 assert!(!nan.is_normal());
1189 assert!(!nan.is_sign_positive());
1190 assert!(!nan.is_sign_negative());
1191 assert_eq!(Fp::Nan, nan.classify());
1195 fn test_infinity() {
1196 let inf: f32 = f32::INFINITY;
1197 assert!(inf.is_infinite());
1198 assert!(!inf.is_finite());
1199 assert!(inf.is_sign_positive());
1200 assert!(!inf.is_sign_negative());
1201 assert!(!inf.is_nan());
1202 assert!(!inf.is_normal());
1203 assert_eq!(Fp::Infinite, inf.classify());
1207 fn test_neg_infinity() {
1208 let neg_inf: f32 = f32::NEG_INFINITY;
1209 assert!(neg_inf.is_infinite());
1210 assert!(!neg_inf.is_finite());
1211 assert!(!neg_inf.is_sign_positive());
1212 assert!(neg_inf.is_sign_negative());
1213 assert!(!neg_inf.is_nan());
1214 assert!(!neg_inf.is_normal());
1215 assert_eq!(Fp::Infinite, neg_inf.classify());
1220 let zero: f32 = 0.0f32;
1221 assert_eq!(0.0, zero);
1222 assert!(!zero.is_infinite());
1223 assert!(zero.is_finite());
1224 assert!(zero.is_sign_positive());
1225 assert!(!zero.is_sign_negative());
1226 assert!(!zero.is_nan());
1227 assert!(!zero.is_normal());
1228 assert_eq!(Fp::Zero, zero.classify());
1232 fn test_neg_zero() {
1233 let neg_zero: f32 = -0.0;
1234 assert_eq!(0.0, neg_zero);
1235 assert!(!neg_zero.is_infinite());
1236 assert!(neg_zero.is_finite());
1237 assert!(!neg_zero.is_sign_positive());
1238 assert!(neg_zero.is_sign_negative());
1239 assert!(!neg_zero.is_nan());
1240 assert!(!neg_zero.is_normal());
1241 assert_eq!(Fp::Zero, neg_zero.classify());
1246 let one: f32 = 1.0f32;
1247 assert_eq!(1.0, one);
1248 assert!(!one.is_infinite());
1249 assert!(one.is_finite());
1250 assert!(one.is_sign_positive());
1251 assert!(!one.is_sign_negative());
1252 assert!(!one.is_nan());
1253 assert!(one.is_normal());
1254 assert_eq!(Fp::Normal, one.classify());
1259 let nan: f32 = f32::NAN;
1260 let inf: f32 = f32::INFINITY;
1261 let neg_inf: f32 = f32::NEG_INFINITY;
1262 assert!(nan.is_nan());
1263 assert!(!0.0f32.is_nan());
1264 assert!(!5.3f32.is_nan());
1265 assert!(!(-10.732f32).is_nan());
1266 assert!(!inf.is_nan());
1267 assert!(!neg_inf.is_nan());
1271 fn test_is_infinite() {
1272 let nan: f32 = f32::NAN;
1273 let inf: f32 = f32::INFINITY;
1274 let neg_inf: f32 = f32::NEG_INFINITY;
1275 assert!(!nan.is_infinite());
1276 assert!(inf.is_infinite());
1277 assert!(neg_inf.is_infinite());
1278 assert!(!0.0f32.is_infinite());
1279 assert!(!42.8f32.is_infinite());
1280 assert!(!(-109.2f32).is_infinite());
1284 fn test_is_finite() {
1285 let nan: f32 = f32::NAN;
1286 let inf: f32 = f32::INFINITY;
1287 let neg_inf: f32 = f32::NEG_INFINITY;
1288 assert!(!nan.is_finite());
1289 assert!(!inf.is_finite());
1290 assert!(!neg_inf.is_finite());
1291 assert!(0.0f32.is_finite());
1292 assert!(42.8f32.is_finite());
1293 assert!((-109.2f32).is_finite());
1297 fn test_is_normal() {
1298 let nan: f32 = f32::NAN;
1299 let inf: f32 = f32::INFINITY;
1300 let neg_inf: f32 = f32::NEG_INFINITY;
1301 let zero: f32 = 0.0f32;
1302 let neg_zero: f32 = -0.0;
1303 assert!(!nan.is_normal());
1304 assert!(!inf.is_normal());
1305 assert!(!neg_inf.is_normal());
1306 assert!(!zero.is_normal());
1307 assert!(!neg_zero.is_normal());
1308 assert!(1f32.is_normal());
1309 assert!(1e-37f32.is_normal());
1310 assert!(!1e-38f32.is_normal());
1314 fn test_classify() {
1315 let nan: f32 = f32::NAN;
1316 let inf: f32 = f32::INFINITY;
1317 let neg_inf: f32 = f32::NEG_INFINITY;
1318 let zero: f32 = 0.0f32;
1319 let neg_zero: f32 = -0.0;
1320 assert_eq!(nan.classify(), Fp::Nan);
1321 assert_eq!(inf.classify(), Fp::Infinite);
1322 assert_eq!(neg_inf.classify(), Fp::Infinite);
1323 assert_eq!(zero.classify(), Fp::Zero);
1324 assert_eq!(neg_zero.classify(), Fp::Zero);
1325 assert_eq!(1f32.classify(), Fp::Normal);
1326 assert_eq!(1e-37f32.classify(), Fp::Normal);
1327 assert_eq!(1e-38f32.classify(), Fp::Subnormal);
1332 assert_approx_eq!(1.0f32.floor(), 1.0f32);
1333 assert_approx_eq!(1.3f32.floor(), 1.0f32);
1334 assert_approx_eq!(1.5f32.floor(), 1.0f32);
1335 assert_approx_eq!(1.7f32.floor(), 1.0f32);
1336 assert_approx_eq!(0.0f32.floor(), 0.0f32);
1337 assert_approx_eq!((-0.0f32).floor(), -0.0f32);
1338 assert_approx_eq!((-1.0f32).floor(), -1.0f32);
1339 assert_approx_eq!((-1.3f32).floor(), -2.0f32);
1340 assert_approx_eq!((-1.5f32).floor(), -2.0f32);
1341 assert_approx_eq!((-1.7f32).floor(), -2.0f32);
1346 assert_approx_eq!(1.0f32.ceil(), 1.0f32);
1347 assert_approx_eq!(1.3f32.ceil(), 2.0f32);
1348 assert_approx_eq!(1.5f32.ceil(), 2.0f32);
1349 assert_approx_eq!(1.7f32.ceil(), 2.0f32);
1350 assert_approx_eq!(0.0f32.ceil(), 0.0f32);
1351 assert_approx_eq!((-0.0f32).ceil(), -0.0f32);
1352 assert_approx_eq!((-1.0f32).ceil(), -1.0f32);
1353 assert_approx_eq!((-1.3f32).ceil(), -1.0f32);
1354 assert_approx_eq!((-1.5f32).ceil(), -1.0f32);
1355 assert_approx_eq!((-1.7f32).ceil(), -1.0f32);
1360 assert_approx_eq!(1.0f32.round(), 1.0f32);
1361 assert_approx_eq!(1.3f32.round(), 1.0f32);
1362 assert_approx_eq!(1.5f32.round(), 2.0f32);
1363 assert_approx_eq!(1.7f32.round(), 2.0f32);
1364 assert_approx_eq!(0.0f32.round(), 0.0f32);
1365 assert_approx_eq!((-0.0f32).round(), -0.0f32);
1366 assert_approx_eq!((-1.0f32).round(), -1.0f32);
1367 assert_approx_eq!((-1.3f32).round(), -1.0f32);
1368 assert_approx_eq!((-1.5f32).round(), -2.0f32);
1369 assert_approx_eq!((-1.7f32).round(), -2.0f32);
1374 assert_approx_eq!(1.0f32.trunc(), 1.0f32);
1375 assert_approx_eq!(1.3f32.trunc(), 1.0f32);
1376 assert_approx_eq!(1.5f32.trunc(), 1.0f32);
1377 assert_approx_eq!(1.7f32.trunc(), 1.0f32);
1378 assert_approx_eq!(0.0f32.trunc(), 0.0f32);
1379 assert_approx_eq!((-0.0f32).trunc(), -0.0f32);
1380 assert_approx_eq!((-1.0f32).trunc(), -1.0f32);
1381 assert_approx_eq!((-1.3f32).trunc(), -1.0f32);
1382 assert_approx_eq!((-1.5f32).trunc(), -1.0f32);
1383 assert_approx_eq!((-1.7f32).trunc(), -1.0f32);
1388 assert_approx_eq!(1.0f32.fract(), 0.0f32);
1389 assert_approx_eq!(1.3f32.fract(), 0.3f32);
1390 assert_approx_eq!(1.5f32.fract(), 0.5f32);
1391 assert_approx_eq!(1.7f32.fract(), 0.7f32);
1392 assert_approx_eq!(0.0f32.fract(), 0.0f32);
1393 assert_approx_eq!((-0.0f32).fract(), -0.0f32);
1394 assert_approx_eq!((-1.0f32).fract(), -0.0f32);
1395 assert_approx_eq!((-1.3f32).fract(), -0.3f32);
1396 assert_approx_eq!((-1.5f32).fract(), -0.5f32);
1397 assert_approx_eq!((-1.7f32).fract(), -0.7f32);
1402 assert_eq!(INFINITY.abs(), INFINITY);
1403 assert_eq!(1f32.abs(), 1f32);
1404 assert_eq!(0f32.abs(), 0f32);
1405 assert_eq!((-0f32).abs(), 0f32);
1406 assert_eq!((-1f32).abs(), 1f32);
1407 assert_eq!(NEG_INFINITY.abs(), INFINITY);
1408 assert_eq!((1f32/NEG_INFINITY).abs(), 0f32);
1409 assert!(NAN.abs().is_nan());
1414 assert_eq!(INFINITY.signum(), 1f32);
1415 assert_eq!(1f32.signum(), 1f32);
1416 assert_eq!(0f32.signum(), 1f32);
1417 assert_eq!((-0f32).signum(), -1f32);
1418 assert_eq!((-1f32).signum(), -1f32);
1419 assert_eq!(NEG_INFINITY.signum(), -1f32);
1420 assert_eq!((1f32/NEG_INFINITY).signum(), -1f32);
1421 assert!(NAN.signum().is_nan());
1425 fn test_is_sign_positive() {
1426 assert!(INFINITY.is_sign_positive());
1427 assert!(1f32.is_sign_positive());
1428 assert!(0f32.is_sign_positive());
1429 assert!(!(-0f32).is_sign_positive());
1430 assert!(!(-1f32).is_sign_positive());
1431 assert!(!NEG_INFINITY.is_sign_positive());
1432 assert!(!(1f32/NEG_INFINITY).is_sign_positive());
1433 assert!(!NAN.is_sign_positive());
1437 fn test_is_sign_negative() {
1438 assert!(!INFINITY.is_sign_negative());
1439 assert!(!1f32.is_sign_negative());
1440 assert!(!0f32.is_sign_negative());
1441 assert!((-0f32).is_sign_negative());
1442 assert!((-1f32).is_sign_negative());
1443 assert!(NEG_INFINITY.is_sign_negative());
1444 assert!((1f32/NEG_INFINITY).is_sign_negative());
1445 assert!(!NAN.is_sign_negative());
1450 let nan: f32 = f32::NAN;
1451 let inf: f32 = f32::INFINITY;
1452 let neg_inf: f32 = f32::NEG_INFINITY;
1453 assert_approx_eq!(12.3f32.mul_add(4.5, 6.7), 62.05);
1454 assert_approx_eq!((-12.3f32).mul_add(-4.5, -6.7), 48.65);
1455 assert_approx_eq!(0.0f32.mul_add(8.9, 1.2), 1.2);
1456 assert_approx_eq!(3.4f32.mul_add(-0.0, 5.6), 5.6);
1457 assert!(nan.mul_add(7.8, 9.0).is_nan());
1458 assert_eq!(inf.mul_add(7.8, 9.0), inf);
1459 assert_eq!(neg_inf.mul_add(7.8, 9.0), neg_inf);
1460 assert_eq!(8.9f32.mul_add(inf, 3.2), inf);
1461 assert_eq!((-3.2f32).mul_add(2.4, neg_inf), neg_inf);
1466 let nan: f32 = f32::NAN;
1467 let inf: f32 = f32::INFINITY;
1468 let neg_inf: f32 = f32::NEG_INFINITY;
1469 assert_eq!(1.0f32.recip(), 1.0);
1470 assert_eq!(2.0f32.recip(), 0.5);
1471 assert_eq!((-0.4f32).recip(), -2.5);
1472 assert_eq!(0.0f32.recip(), inf);
1473 assert!(nan.recip().is_nan());
1474 assert_eq!(inf.recip(), 0.0);
1475 assert_eq!(neg_inf.recip(), 0.0);
1480 let nan: f32 = f32::NAN;
1481 let inf: f32 = f32::INFINITY;
1482 let neg_inf: f32 = f32::NEG_INFINITY;
1483 assert_eq!(1.0f32.powi(1), 1.0);
1484 assert_approx_eq!((-3.1f32).powi(2), 9.61);
1485 assert_approx_eq!(5.9f32.powi(-2), 0.028727);
1486 assert_eq!(8.3f32.powi(0), 1.0);
1487 assert!(nan.powi(2).is_nan());
1488 assert_eq!(inf.powi(3), inf);
1489 assert_eq!(neg_inf.powi(2), inf);
1494 let nan: f32 = f32::NAN;
1495 let inf: f32 = f32::INFINITY;
1496 let neg_inf: f32 = f32::NEG_INFINITY;
1497 assert_eq!(1.0f32.powf(1.0), 1.0);
1498 assert_approx_eq!(3.4f32.powf(4.5), 246.408218);
1499 assert_approx_eq!(2.7f32.powf(-3.2), 0.041652);
1500 assert_approx_eq!((-3.1f32).powf(2.0), 9.61);
1501 assert_approx_eq!(5.9f32.powf(-2.0), 0.028727);
1502 assert_eq!(8.3f32.powf(0.0), 1.0);
1503 assert!(nan.powf(2.0).is_nan());
1504 assert_eq!(inf.powf(2.0), inf);
1505 assert_eq!(neg_inf.powf(3.0), neg_inf);
1509 fn test_sqrt_domain() {
1510 assert!(NAN.sqrt().is_nan());
1511 assert!(NEG_INFINITY.sqrt().is_nan());
1512 assert!((-1.0f32).sqrt().is_nan());
1513 assert_eq!((-0.0f32).sqrt(), -0.0);
1514 assert_eq!(0.0f32.sqrt(), 0.0);
1515 assert_eq!(1.0f32.sqrt(), 1.0);
1516 assert_eq!(INFINITY.sqrt(), INFINITY);
1521 assert_eq!(1.0, 0.0f32.exp());
1522 assert_approx_eq!(2.718282, 1.0f32.exp());
1523 assert_approx_eq!(148.413162, 5.0f32.exp());
1525 let inf: f32 = f32::INFINITY;
1526 let neg_inf: f32 = f32::NEG_INFINITY;
1527 let nan: f32 = f32::NAN;
1528 assert_eq!(inf, inf.exp());
1529 assert_eq!(0.0, neg_inf.exp());
1530 assert!(nan.exp().is_nan());
1535 assert_eq!(32.0, 5.0f32.exp2());
1536 assert_eq!(1.0, 0.0f32.exp2());
1538 let inf: f32 = f32::INFINITY;
1539 let neg_inf: f32 = f32::NEG_INFINITY;
1540 let nan: f32 = f32::NAN;
1541 assert_eq!(inf, inf.exp2());
1542 assert_eq!(0.0, neg_inf.exp2());
1543 assert!(nan.exp2().is_nan());
1548 let nan: f32 = f32::NAN;
1549 let inf: f32 = f32::INFINITY;
1550 let neg_inf: f32 = f32::NEG_INFINITY;
1551 assert_approx_eq!(1.0f32.exp().ln(), 1.0);
1552 assert!(nan.ln().is_nan());
1553 assert_eq!(inf.ln(), inf);
1554 assert!(neg_inf.ln().is_nan());
1555 assert!((-2.3f32).ln().is_nan());
1556 assert_eq!((-0.0f32).ln(), neg_inf);
1557 assert_eq!(0.0f32.ln(), neg_inf);
1558 assert_approx_eq!(4.0f32.ln(), 1.386294);
1563 let nan: f32 = f32::NAN;
1564 let inf: f32 = f32::INFINITY;
1565 let neg_inf: f32 = f32::NEG_INFINITY;
1566 assert_eq!(10.0f32.log(10.0), 1.0);
1567 assert_approx_eq!(2.3f32.log(3.5), 0.664858);
1568 assert_eq!(1.0f32.exp().log(1.0f32.exp()), 1.0);
1569 assert!(1.0f32.log(1.0).is_nan());
1570 assert!(1.0f32.log(-13.9).is_nan());
1571 assert!(nan.log(2.3).is_nan());
1572 assert_eq!(inf.log(10.0), inf);
1573 assert!(neg_inf.log(8.8).is_nan());
1574 assert!((-2.3f32).log(0.1).is_nan());
1575 assert_eq!((-0.0f32).log(2.0), neg_inf);
1576 assert_eq!(0.0f32.log(7.0), neg_inf);
1581 let nan: f32 = f32::NAN;
1582 let inf: f32 = f32::INFINITY;
1583 let neg_inf: f32 = f32::NEG_INFINITY;
1584 assert_approx_eq!(10.0f32.log2(), 3.321928);
1585 assert_approx_eq!(2.3f32.log2(), 1.201634);
1586 assert_approx_eq!(1.0f32.exp().log2(), 1.442695);
1587 assert!(nan.log2().is_nan());
1588 assert_eq!(inf.log2(), inf);
1589 assert!(neg_inf.log2().is_nan());
1590 assert!((-2.3f32).log2().is_nan());
1591 assert_eq!((-0.0f32).log2(), neg_inf);
1592 assert_eq!(0.0f32.log2(), neg_inf);
1597 let nan: f32 = f32::NAN;
1598 let inf: f32 = f32::INFINITY;
1599 let neg_inf: f32 = f32::NEG_INFINITY;
1600 assert_eq!(10.0f32.log10(), 1.0);
1601 assert_approx_eq!(2.3f32.log10(), 0.361728);
1602 assert_approx_eq!(1.0f32.exp().log10(), 0.434294);
1603 assert_eq!(1.0f32.log10(), 0.0);
1604 assert!(nan.log10().is_nan());
1605 assert_eq!(inf.log10(), inf);
1606 assert!(neg_inf.log10().is_nan());
1607 assert!((-2.3f32).log10().is_nan());
1608 assert_eq!((-0.0f32).log10(), neg_inf);
1609 assert_eq!(0.0f32.log10(), neg_inf);
1613 fn test_to_degrees() {
1614 let pi: f32 = consts::PI;
1615 let nan: f32 = f32::NAN;
1616 let inf: f32 = f32::INFINITY;
1617 let neg_inf: f32 = f32::NEG_INFINITY;
1618 assert_eq!(0.0f32.to_degrees(), 0.0);
1619 assert_approx_eq!((-5.8f32).to_degrees(), -332.315521);
1620 assert_eq!(pi.to_degrees(), 180.0);
1621 assert!(nan.to_degrees().is_nan());
1622 assert_eq!(inf.to_degrees(), inf);
1623 assert_eq!(neg_inf.to_degrees(), neg_inf);
1627 fn test_to_radians() {
1628 let pi: f32 = consts::PI;
1629 let nan: f32 = f32::NAN;
1630 let inf: f32 = f32::INFINITY;
1631 let neg_inf: f32 = f32::NEG_INFINITY;
1632 assert_eq!(0.0f32.to_radians(), 0.0);
1633 assert_approx_eq!(154.6f32.to_radians(), 2.698279);
1634 assert_approx_eq!((-332.31f32).to_radians(), -5.799903);
1635 assert_eq!(180.0f32.to_radians(), pi);
1636 assert!(nan.to_radians().is_nan());
1637 assert_eq!(inf.to_radians(), inf);
1638 assert_eq!(neg_inf.to_radians(), neg_inf);
1643 assert_eq!(0.0f32.asinh(), 0.0f32);
1644 assert_eq!((-0.0f32).asinh(), -0.0f32);
1646 let inf: f32 = f32::INFINITY;
1647 let neg_inf: f32 = f32::NEG_INFINITY;
1648 let nan: f32 = f32::NAN;
1649 assert_eq!(inf.asinh(), inf);
1650 assert_eq!(neg_inf.asinh(), neg_inf);
1651 assert!(nan.asinh().is_nan());
1652 assert_approx_eq!(2.0f32.asinh(), 1.443635475178810342493276740273105f32);
1653 assert_approx_eq!((-2.0f32).asinh(), -1.443635475178810342493276740273105f32);
1658 assert_eq!(1.0f32.acosh(), 0.0f32);
1659 assert!(0.999f32.acosh().is_nan());
1661 let inf: f32 = f32::INFINITY;
1662 let neg_inf: f32 = f32::NEG_INFINITY;
1663 let nan: f32 = f32::NAN;
1664 assert_eq!(inf.acosh(), inf);
1665 assert!(neg_inf.acosh().is_nan());
1666 assert!(nan.acosh().is_nan());
1667 assert_approx_eq!(2.0f32.acosh(), 1.31695789692481670862504634730796844f32);
1668 assert_approx_eq!(3.0f32.acosh(), 1.76274717403908605046521864995958461f32);
1673 assert_eq!(0.0f32.atanh(), 0.0f32);
1674 assert_eq!((-0.0f32).atanh(), -0.0f32);
1676 let inf32: f32 = f32::INFINITY;
1677 let neg_inf32: f32 = f32::NEG_INFINITY;
1678 assert_eq!(1.0f32.atanh(), inf32);
1679 assert_eq!((-1.0f32).atanh(), neg_inf32);
1681 assert!(2f64.atanh().atanh().is_nan());
1682 assert!((-2f64).atanh().atanh().is_nan());
1684 let inf64: f32 = f32::INFINITY;
1685 let neg_inf64: f32 = f32::NEG_INFINITY;
1686 let nan32: f32 = f32::NAN;
1687 assert!(inf64.atanh().is_nan());
1688 assert!(neg_inf64.atanh().is_nan());
1689 assert!(nan32.atanh().is_nan());
1691 assert_approx_eq!(0.5f32.atanh(), 0.54930614433405484569762261846126285f32);
1692 assert_approx_eq!((-0.5f32).atanh(), -0.54930614433405484569762261846126285f32);
1696 fn test_real_consts() {
1699 let pi: f32 = consts::PI;
1700 let frac_pi_2: f32 = consts::FRAC_PI_2;
1701 let frac_pi_3: f32 = consts::FRAC_PI_3;
1702 let frac_pi_4: f32 = consts::FRAC_PI_4;
1703 let frac_pi_6: f32 = consts::FRAC_PI_6;
1704 let frac_pi_8: f32 = consts::FRAC_PI_8;
1705 let frac_1_pi: f32 = consts::FRAC_1_PI;
1706 let frac_2_pi: f32 = consts::FRAC_2_PI;
1707 let frac_2_sqrtpi: f32 = consts::FRAC_2_SQRT_PI;
1708 let sqrt2: f32 = consts::SQRT_2;
1709 let frac_1_sqrt2: f32 = consts::FRAC_1_SQRT_2;
1710 let e: f32 = consts::E;
1711 let log2_e: f32 = consts::LOG2_E;
1712 let log10_e: f32 = consts::LOG10_E;
1713 let ln_2: f32 = consts::LN_2;
1714 let ln_10: f32 = consts::LN_10;
1716 assert_approx_eq!(frac_pi_2, pi / 2f32);
1717 assert_approx_eq!(frac_pi_3, pi / 3f32);
1718 assert_approx_eq!(frac_pi_4, pi / 4f32);
1719 assert_approx_eq!(frac_pi_6, pi / 6f32);
1720 assert_approx_eq!(frac_pi_8, pi / 8f32);
1721 assert_approx_eq!(frac_1_pi, 1f32 / pi);
1722 assert_approx_eq!(frac_2_pi, 2f32 / pi);
1723 assert_approx_eq!(frac_2_sqrtpi, 2f32 / pi.sqrt());
1724 assert_approx_eq!(sqrt2, 2f32.sqrt());
1725 assert_approx_eq!(frac_1_sqrt2, 1f32 / 2f32.sqrt());
1726 assert_approx_eq!(log2_e, e.log2());
1727 assert_approx_eq!(log10_e, e.log10());
1728 assert_approx_eq!(ln_2, 2f32.ln());
1729 assert_approx_eq!(ln_10, 10f32.ln());
1733 fn test_float_bits_conv() {
1734 assert_eq!((1f32).to_bits(), 0x3f800000);
1735 assert_eq!((12.5f32).to_bits(), 0x41480000);
1736 assert_eq!((1337f32).to_bits(), 0x44a72000);
1737 assert_eq!((-14.25f32).to_bits(), 0xc1640000);
1738 assert_approx_eq!(f32::from_bits(0x3f800000), 1.0);
1739 assert_approx_eq!(f32::from_bits(0x41480000), 12.5);
1740 assert_approx_eq!(f32::from_bits(0x44a72000), 1337.0);
1741 assert_approx_eq!(f32::from_bits(0xc1640000), -14.25);
1744 fn test_snan_masking() {
1745 let snan: u32 = 0x7F801337;
1746 const PAYLOAD_MASK: u32 = 0x003FFFFF;
1747 const QNAN_MASK: u32 = 0x00400000;
1748 let nan_masked_fl = f32::from_bits(snan);
1749 let nan_masked = nan_masked_fl.to_bits();
1750 // Ensure that signaling NaNs don't stay the same
1751 assert_ne!(nan_masked, snan);
1752 // Ensure that we have a quiet NaN
1753 assert_ne!(nan_masked & QNAN_MASK, 0);
1754 assert!(nan_masked_fl.is_nan());
1755 // Ensure the payload wasn't touched during conversion
1756 assert_eq!(nan_masked & PAYLOAD_MASK, snan & PAYLOAD_MASK);