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 and only if `self` has a positive sign, including `+0.0`, `NaN`s with
369 /// positive sign bit and positive infinity.
373 /// let g = -7.0_f32;
375 /// assert!(f.is_sign_positive());
376 /// assert!(!g.is_sign_positive());
378 #[stable(feature = "rust1", since = "1.0.0")]
380 pub fn is_sign_positive(self) -> bool { num::Float::is_sign_positive(self) }
382 /// Returns `true` if and only if `self` has a negative sign, including `-0.0`, `NaN`s with
383 /// negative sign bit and negative infinity.
389 /// assert!(!f.is_sign_negative());
390 /// assert!(g.is_sign_negative());
392 #[stable(feature = "rust1", since = "1.0.0")]
394 pub fn is_sign_negative(self) -> bool { num::Float::is_sign_negative(self) }
396 /// Fused multiply-add. Computes `(self * a) + b` with only one rounding
397 /// error. This produces a more accurate result with better performance than
398 /// a separate multiplication operation followed by an add.
403 /// let m = 10.0_f32;
405 /// let b = 60.0_f32;
408 /// let abs_difference = (m.mul_add(x, b) - (m*x + b)).abs();
410 /// assert!(abs_difference <= f32::EPSILON);
412 #[stable(feature = "rust1", since = "1.0.0")]
414 pub fn mul_add(self, a: f32, b: f32) -> f32 {
415 unsafe { intrinsics::fmaf32(self, a, b) }
418 /// Takes the reciprocal (inverse) of a number, `1/x`.
424 /// let abs_difference = (x.recip() - (1.0/x)).abs();
426 /// assert!(abs_difference <= f32::EPSILON);
428 #[stable(feature = "rust1", since = "1.0.0")]
430 pub fn recip(self) -> f32 { num::Float::recip(self) }
432 /// Raises a number to an integer power.
434 /// Using this function is generally faster than using `powf`
440 /// let abs_difference = (x.powi(2) - x*x).abs();
442 /// assert!(abs_difference <= f32::EPSILON);
444 #[stable(feature = "rust1", since = "1.0.0")]
446 pub fn powi(self, n: i32) -> f32 { num::Float::powi(self, n) }
448 /// Raises a number to a floating point power.
454 /// let abs_difference = (x.powf(2.0) - x*x).abs();
456 /// assert!(abs_difference <= f32::EPSILON);
458 #[stable(feature = "rust1", since = "1.0.0")]
460 pub fn powf(self, n: f32) -> f32 {
461 // see notes above in `floor`
462 #[cfg(target_env = "msvc")]
463 return (self as f64).powf(n as f64) as f32;
464 #[cfg(not(target_env = "msvc"))]
465 return unsafe { intrinsics::powf32(self, n) };
468 /// Takes the square root of a number.
470 /// Returns NaN if `self` is a negative number.
475 /// let positive = 4.0_f32;
476 /// let negative = -4.0_f32;
478 /// let abs_difference = (positive.sqrt() - 2.0).abs();
480 /// assert!(abs_difference <= f32::EPSILON);
481 /// assert!(negative.sqrt().is_nan());
483 #[stable(feature = "rust1", since = "1.0.0")]
485 pub fn sqrt(self) -> f32 {
489 unsafe { intrinsics::sqrtf32(self) }
493 /// Returns `e^(self)`, (the exponential function).
498 /// let one = 1.0f32;
500 /// let e = one.exp();
502 /// // ln(e) - 1 == 0
503 /// let abs_difference = (e.ln() - 1.0).abs();
505 /// assert!(abs_difference <= f32::EPSILON);
507 #[stable(feature = "rust1", since = "1.0.0")]
509 pub fn exp(self) -> f32 {
510 // see notes above in `floor`
511 #[cfg(target_env = "msvc")]
512 return (self as f64).exp() as f32;
513 #[cfg(not(target_env = "msvc"))]
514 return unsafe { intrinsics::expf32(self) };
517 /// Returns `2^(self)`.
525 /// let abs_difference = (f.exp2() - 4.0).abs();
527 /// assert!(abs_difference <= f32::EPSILON);
529 #[stable(feature = "rust1", since = "1.0.0")]
531 pub fn exp2(self) -> f32 {
532 unsafe { intrinsics::exp2f32(self) }
535 /// Returns the natural logarithm of the number.
540 /// let one = 1.0f32;
542 /// let e = one.exp();
544 /// // ln(e) - 1 == 0
545 /// let abs_difference = (e.ln() - 1.0).abs();
547 /// assert!(abs_difference <= f32::EPSILON);
549 #[stable(feature = "rust1", since = "1.0.0")]
551 pub fn ln(self) -> f32 {
552 // see notes above in `floor`
553 #[cfg(target_env = "msvc")]
554 return (self as f64).ln() as f32;
555 #[cfg(not(target_env = "msvc"))]
556 return unsafe { intrinsics::logf32(self) };
559 /// Returns the logarithm of the number with respect to an arbitrary base.
564 /// let ten = 10.0f32;
565 /// let two = 2.0f32;
567 /// // log10(10) - 1 == 0
568 /// let abs_difference_10 = (ten.log(10.0) - 1.0).abs();
570 /// // log2(2) - 1 == 0
571 /// let abs_difference_2 = (two.log(2.0) - 1.0).abs();
573 /// assert!(abs_difference_10 <= f32::EPSILON);
574 /// assert!(abs_difference_2 <= f32::EPSILON);
576 #[stable(feature = "rust1", since = "1.0.0")]
578 pub fn log(self, base: f32) -> f32 { self.ln() / base.ln() }
580 /// Returns the base 2 logarithm of the number.
585 /// let two = 2.0f32;
587 /// // log2(2) - 1 == 0
588 /// let abs_difference = (two.log2() - 1.0).abs();
590 /// assert!(abs_difference <= f32::EPSILON);
592 #[stable(feature = "rust1", since = "1.0.0")]
594 pub fn log2(self) -> f32 {
595 #[cfg(target_os = "android")]
596 return ::sys::android::log2f32(self);
597 #[cfg(not(target_os = "android"))]
598 return unsafe { intrinsics::log2f32(self) };
601 /// Returns the base 10 logarithm of the number.
606 /// let ten = 10.0f32;
608 /// // log10(10) - 1 == 0
609 /// let abs_difference = (ten.log10() - 1.0).abs();
611 /// assert!(abs_difference <= f32::EPSILON);
613 #[stable(feature = "rust1", since = "1.0.0")]
615 pub fn log10(self) -> f32 {
616 // see notes above in `floor`
617 #[cfg(target_env = "msvc")]
618 return (self as f64).log10() as f32;
619 #[cfg(not(target_env = "msvc"))]
620 return unsafe { intrinsics::log10f32(self) };
623 /// Converts radians to degrees.
626 /// use std::f32::{self, consts};
628 /// let angle = consts::PI;
630 /// let abs_difference = (angle.to_degrees() - 180.0).abs();
632 /// assert!(abs_difference <= f32::EPSILON);
634 #[stable(feature = "f32_deg_rad_conversions", since="1.7.0")]
636 pub fn to_degrees(self) -> f32 { num::Float::to_degrees(self) }
638 /// Converts degrees to radians.
641 /// use std::f32::{self, consts};
643 /// let angle = 180.0f32;
645 /// let abs_difference = (angle.to_radians() - consts::PI).abs();
647 /// assert!(abs_difference <= f32::EPSILON);
649 #[stable(feature = "f32_deg_rad_conversions", since="1.7.0")]
651 pub fn to_radians(self) -> f32 { num::Float::to_radians(self) }
653 /// Returns the maximum of the two numbers.
659 /// assert_eq!(x.max(y), y);
662 /// If one of the arguments is NaN, then the other argument is returned.
663 #[stable(feature = "rust1", since = "1.0.0")]
665 pub fn max(self, other: f32) -> f32 {
666 unsafe { cmath::fmaxf(self, other) }
669 /// Returns the minimum of the two numbers.
675 /// assert_eq!(x.min(y), x);
678 /// If one of the arguments is NaN, then the other argument is returned.
679 #[stable(feature = "rust1", since = "1.0.0")]
681 pub fn min(self, other: f32) -> f32 {
682 unsafe { cmath::fminf(self, other) }
685 /// The positive difference of two numbers.
687 /// * If `self <= other`: `0:0`
688 /// * Else: `self - other`
696 /// let abs_difference_x = (x.abs_sub(1.0) - 2.0).abs();
697 /// let abs_difference_y = (y.abs_sub(1.0) - 0.0).abs();
699 /// assert!(abs_difference_x <= f32::EPSILON);
700 /// assert!(abs_difference_y <= f32::EPSILON);
702 #[stable(feature = "rust1", since = "1.0.0")]
704 #[rustc_deprecated(since = "1.10.0",
705 reason = "you probably meant `(self - other).abs()`: \
706 this operation is `(self - other).max(0.0)` (also \
707 known as `fdimf` in C). If you truly need the positive \
708 difference, consider using that expression or the C function \
709 `fdimf`, depending on how you wish to handle NaN (please consider \
710 filing an issue describing your use-case too).")]
711 pub fn abs_sub(self, other: f32) -> f32 {
712 unsafe { cmath::fdimf(self, other) }
715 /// Takes the cubic root of a number.
722 /// // x^(1/3) - 2 == 0
723 /// let abs_difference = (x.cbrt() - 2.0).abs();
725 /// assert!(abs_difference <= f32::EPSILON);
727 #[stable(feature = "rust1", since = "1.0.0")]
729 pub fn cbrt(self) -> f32 {
730 unsafe { cmath::cbrtf(self) }
733 /// Calculates the length of the hypotenuse of a right-angle triangle given
734 /// legs of length `x` and `y`.
742 /// // sqrt(x^2 + y^2)
743 /// let abs_difference = (x.hypot(y) - (x.powi(2) + y.powi(2)).sqrt()).abs();
745 /// assert!(abs_difference <= f32::EPSILON);
747 #[stable(feature = "rust1", since = "1.0.0")]
749 pub fn hypot(self, other: f32) -> f32 {
750 unsafe { cmath::hypotf(self, other) }
753 /// Computes the sine of a number (in radians).
758 /// let x = f32::consts::PI/2.0;
760 /// let abs_difference = (x.sin() - 1.0).abs();
762 /// assert!(abs_difference <= f32::EPSILON);
764 #[stable(feature = "rust1", since = "1.0.0")]
766 pub fn sin(self) -> f32 {
767 // see notes in `core::f32::Float::floor`
768 #[cfg(target_env = "msvc")]
769 return (self as f64).sin() as f32;
770 #[cfg(not(target_env = "msvc"))]
771 return unsafe { intrinsics::sinf32(self) };
774 /// Computes the cosine of a number (in radians).
779 /// let x = 2.0*f32::consts::PI;
781 /// let abs_difference = (x.cos() - 1.0).abs();
783 /// assert!(abs_difference <= f32::EPSILON);
785 #[stable(feature = "rust1", since = "1.0.0")]
787 pub fn cos(self) -> f32 {
788 // see notes in `core::f32::Float::floor`
789 #[cfg(target_env = "msvc")]
790 return (self as f64).cos() as f32;
791 #[cfg(not(target_env = "msvc"))]
792 return unsafe { intrinsics::cosf32(self) };
795 /// Computes the tangent of a number (in radians).
800 /// let x = f32::consts::PI / 4.0;
801 /// let abs_difference = (x.tan() - 1.0).abs();
803 /// assert!(abs_difference <= f32::EPSILON);
805 #[stable(feature = "rust1", since = "1.0.0")]
807 pub fn tan(self) -> f32 {
808 unsafe { cmath::tanf(self) }
811 /// Computes the arcsine of a number. Return value is in radians in
812 /// the range [-pi/2, pi/2] or NaN if the number is outside the range
818 /// let f = f32::consts::PI / 2.0;
820 /// // asin(sin(pi/2))
821 /// let abs_difference = (f.sin().asin() - f32::consts::PI / 2.0).abs();
823 /// assert!(abs_difference <= f32::EPSILON);
825 #[stable(feature = "rust1", since = "1.0.0")]
827 pub fn asin(self) -> f32 {
828 unsafe { cmath::asinf(self) }
831 /// Computes the arccosine of a number. Return value is in radians in
832 /// the range [0, pi] or NaN if the number is outside the range
838 /// let f = f32::consts::PI / 4.0;
840 /// // acos(cos(pi/4))
841 /// let abs_difference = (f.cos().acos() - f32::consts::PI / 4.0).abs();
843 /// assert!(abs_difference <= f32::EPSILON);
845 #[stable(feature = "rust1", since = "1.0.0")]
847 pub fn acos(self) -> f32 {
848 unsafe { cmath::acosf(self) }
851 /// Computes the arctangent of a number. Return value is in radians in the
852 /// range [-pi/2, pi/2];
860 /// let abs_difference = (f.tan().atan() - 1.0).abs();
862 /// assert!(abs_difference <= f32::EPSILON);
864 #[stable(feature = "rust1", since = "1.0.0")]
866 pub fn atan(self) -> f32 {
867 unsafe { cmath::atanf(self) }
870 /// Computes the four quadrant arctangent of `self` (`y`) and `other` (`x`).
872 /// * `x = 0`, `y = 0`: `0`
873 /// * `x >= 0`: `arctan(y/x)` -> `[-pi/2, pi/2]`
874 /// * `y >= 0`: `arctan(y/x) + pi` -> `(pi/2, pi]`
875 /// * `y < 0`: `arctan(y/x) - pi` -> `(-pi, -pi/2)`
880 /// let pi = f32::consts::PI;
881 /// // All angles from horizontal right (+x)
882 /// // 45 deg counter-clockwise
884 /// let y1 = -3.0f32;
886 /// // 135 deg clockwise
887 /// let x2 = -3.0f32;
890 /// let abs_difference_1 = (y1.atan2(x1) - (-pi/4.0)).abs();
891 /// let abs_difference_2 = (y2.atan2(x2) - 3.0*pi/4.0).abs();
893 /// assert!(abs_difference_1 <= f32::EPSILON);
894 /// assert!(abs_difference_2 <= f32::EPSILON);
896 #[stable(feature = "rust1", since = "1.0.0")]
898 pub fn atan2(self, other: f32) -> f32 {
899 unsafe { cmath::atan2f(self, other) }
902 /// Simultaneously computes the sine and cosine of the number, `x`. Returns
903 /// `(sin(x), cos(x))`.
908 /// let x = f32::consts::PI/4.0;
909 /// let f = x.sin_cos();
911 /// let abs_difference_0 = (f.0 - x.sin()).abs();
912 /// let abs_difference_1 = (f.1 - x.cos()).abs();
914 /// assert!(abs_difference_0 <= f32::EPSILON);
915 /// assert!(abs_difference_1 <= f32::EPSILON);
917 #[stable(feature = "rust1", since = "1.0.0")]
919 pub fn sin_cos(self) -> (f32, f32) {
920 (self.sin(), self.cos())
923 /// Returns `e^(self) - 1` in a way that is accurate even if the
924 /// number is close to zero.
932 /// let abs_difference = (x.ln().exp_m1() - 5.0).abs();
934 /// assert!(abs_difference <= f32::EPSILON);
936 #[stable(feature = "rust1", since = "1.0.0")]
938 pub fn exp_m1(self) -> f32 {
939 unsafe { cmath::expm1f(self) }
942 /// Returns `ln(1+n)` (natural logarithm) more accurately than if
943 /// the operations were performed separately.
948 /// let x = f32::consts::E - 1.0;
950 /// // ln(1 + (e - 1)) == ln(e) == 1
951 /// let abs_difference = (x.ln_1p() - 1.0).abs();
953 /// assert!(abs_difference <= f32::EPSILON);
955 #[stable(feature = "rust1", since = "1.0.0")]
957 pub fn ln_1p(self) -> f32 {
958 unsafe { cmath::log1pf(self) }
961 /// Hyperbolic sine function.
966 /// let e = f32::consts::E;
969 /// let f = x.sinh();
970 /// // Solving sinh() at 1 gives `(e^2-1)/(2e)`
971 /// let g = (e*e - 1.0)/(2.0*e);
972 /// let abs_difference = (f - g).abs();
974 /// assert!(abs_difference <= f32::EPSILON);
976 #[stable(feature = "rust1", since = "1.0.0")]
978 pub fn sinh(self) -> f32 {
979 unsafe { cmath::sinhf(self) }
982 /// Hyperbolic cosine function.
987 /// let e = f32::consts::E;
989 /// let f = x.cosh();
990 /// // Solving cosh() at 1 gives this result
991 /// let g = (e*e + 1.0)/(2.0*e);
992 /// let abs_difference = (f - g).abs();
995 /// assert!(abs_difference <= f32::EPSILON);
997 #[stable(feature = "rust1", since = "1.0.0")]
999 pub fn cosh(self) -> f32 {
1000 unsafe { cmath::coshf(self) }
1003 /// Hyperbolic tangent function.
1008 /// let e = f32::consts::E;
1011 /// let f = x.tanh();
1012 /// // Solving tanh() at 1 gives `(1 - e^(-2))/(1 + e^(-2))`
1013 /// let g = (1.0 - e.powi(-2))/(1.0 + e.powi(-2));
1014 /// let abs_difference = (f - g).abs();
1016 /// assert!(abs_difference <= f32::EPSILON);
1018 #[stable(feature = "rust1", since = "1.0.0")]
1020 pub fn tanh(self) -> f32 {
1021 unsafe { cmath::tanhf(self) }
1024 /// Inverse hyperbolic sine function.
1030 /// let f = x.sinh().asinh();
1032 /// let abs_difference = (f - x).abs();
1034 /// assert!(abs_difference <= f32::EPSILON);
1036 #[stable(feature = "rust1", since = "1.0.0")]
1038 pub fn asinh(self) -> f32 {
1039 if self == NEG_INFINITY {
1042 (self + ((self * self) + 1.0).sqrt()).ln()
1046 /// Inverse hyperbolic cosine function.
1052 /// let f = x.cosh().acosh();
1054 /// let abs_difference = (f - x).abs();
1056 /// assert!(abs_difference <= f32::EPSILON);
1058 #[stable(feature = "rust1", since = "1.0.0")]
1060 pub fn acosh(self) -> f32 {
1062 x if x < 1.0 => ::f32::NAN,
1063 x => (x + ((x * x) - 1.0).sqrt()).ln(),
1067 /// Inverse hyperbolic tangent function.
1072 /// let e = f32::consts::E;
1073 /// let f = e.tanh().atanh();
1075 /// let abs_difference = (f - e).abs();
1077 /// assert!(abs_difference <= 1e-5);
1079 #[stable(feature = "rust1", since = "1.0.0")]
1081 pub fn atanh(self) -> f32 {
1082 0.5 * ((2.0 * self) / (1.0 - self)).ln_1p()
1085 /// Raw transmutation to `u32`.
1087 /// Converts the `f32` into its raw memory representation,
1088 /// similar to the `transmute` function.
1090 /// Note that this function is distinct from casting.
1095 /// #![feature(float_bits_conv)]
1096 /// assert_ne!((1f32).to_bits(), 1f32 as u32); // to_bits() is not casting!
1097 /// assert_eq!((12.5f32).to_bits(), 0x41480000);
1100 #[unstable(feature = "float_bits_conv", reason = "recently added", issue = "40470")]
1102 pub fn to_bits(self) -> u32 {
1103 unsafe { ::mem::transmute(self) }
1106 /// Raw transmutation from `u32`.
1108 /// Converts the given `u32` containing the float's raw memory
1109 /// representation into the `f32` type, similar to the
1110 /// `transmute` function.
1112 /// There is only one difference to a bare `transmute`:
1113 /// Due to the implications onto Rust's safety promises being
1114 /// uncertain, if the representation of a signaling NaN "sNaN" float
1115 /// is passed to the function, the implementation is allowed to
1116 /// return a quiet NaN instead.
1118 /// Note that this function is distinct from casting.
1123 /// #![feature(float_bits_conv)]
1125 /// let v = f32::from_bits(0x41480000);
1126 /// let difference = (v - 12.5).abs();
1127 /// assert!(difference <= 1e-5);
1128 /// // Example for a signaling NaN value:
1129 /// let snan = 0x7F800001;
1130 /// assert_ne!(f32::from_bits(snan).to_bits(), snan);
1132 #[unstable(feature = "float_bits_conv", reason = "recently added", issue = "40470")]
1134 pub fn from_bits(mut v: u32) -> Self {
1135 const EXP_MASK: u32 = 0x7F800000;
1136 const QNAN_MASK: u32 = 0x00400000;
1137 const FRACT_MASK: u32 = 0x007FFFFF;
1138 if v & EXP_MASK == EXP_MASK && v & FRACT_MASK != 0 {
1139 // If we have a NaN value, we
1140 // convert signaling NaN values to quiet NaN
1141 // by setting the the highest bit of the fraction
1144 unsafe { ::mem::transmute(v) }
1153 use num::FpCategory as Fp;
1157 test_num(10f32, 2f32);
1162 assert_eq!(NAN.min(2.0), 2.0);
1163 assert_eq!(2.0f32.min(NAN), 2.0);
1168 assert_eq!(NAN.max(2.0), 2.0);
1169 assert_eq!(2.0f32.max(NAN), 2.0);
1174 let nan: f32 = f32::NAN;
1175 assert!(nan.is_nan());
1176 assert!(!nan.is_infinite());
1177 assert!(!nan.is_finite());
1178 assert!(!nan.is_normal());
1179 assert!(nan.is_sign_positive());
1180 assert!(!nan.is_sign_negative());
1181 assert_eq!(Fp::Nan, nan.classify());
1185 fn test_infinity() {
1186 let inf: f32 = f32::INFINITY;
1187 assert!(inf.is_infinite());
1188 assert!(!inf.is_finite());
1189 assert!(inf.is_sign_positive());
1190 assert!(!inf.is_sign_negative());
1191 assert!(!inf.is_nan());
1192 assert!(!inf.is_normal());
1193 assert_eq!(Fp::Infinite, inf.classify());
1197 fn test_neg_infinity() {
1198 let neg_inf: f32 = f32::NEG_INFINITY;
1199 assert!(neg_inf.is_infinite());
1200 assert!(!neg_inf.is_finite());
1201 assert!(!neg_inf.is_sign_positive());
1202 assert!(neg_inf.is_sign_negative());
1203 assert!(!neg_inf.is_nan());
1204 assert!(!neg_inf.is_normal());
1205 assert_eq!(Fp::Infinite, neg_inf.classify());
1210 let zero: f32 = 0.0f32;
1211 assert_eq!(0.0, zero);
1212 assert!(!zero.is_infinite());
1213 assert!(zero.is_finite());
1214 assert!(zero.is_sign_positive());
1215 assert!(!zero.is_sign_negative());
1216 assert!(!zero.is_nan());
1217 assert!(!zero.is_normal());
1218 assert_eq!(Fp::Zero, zero.classify());
1222 fn test_neg_zero() {
1223 let neg_zero: f32 = -0.0;
1224 assert_eq!(0.0, neg_zero);
1225 assert!(!neg_zero.is_infinite());
1226 assert!(neg_zero.is_finite());
1227 assert!(!neg_zero.is_sign_positive());
1228 assert!(neg_zero.is_sign_negative());
1229 assert!(!neg_zero.is_nan());
1230 assert!(!neg_zero.is_normal());
1231 assert_eq!(Fp::Zero, neg_zero.classify());
1236 let one: f32 = 1.0f32;
1237 assert_eq!(1.0, one);
1238 assert!(!one.is_infinite());
1239 assert!(one.is_finite());
1240 assert!(one.is_sign_positive());
1241 assert!(!one.is_sign_negative());
1242 assert!(!one.is_nan());
1243 assert!(one.is_normal());
1244 assert_eq!(Fp::Normal, one.classify());
1249 let nan: f32 = f32::NAN;
1250 let inf: f32 = f32::INFINITY;
1251 let neg_inf: f32 = f32::NEG_INFINITY;
1252 assert!(nan.is_nan());
1253 assert!(!0.0f32.is_nan());
1254 assert!(!5.3f32.is_nan());
1255 assert!(!(-10.732f32).is_nan());
1256 assert!(!inf.is_nan());
1257 assert!(!neg_inf.is_nan());
1261 fn test_is_infinite() {
1262 let nan: f32 = f32::NAN;
1263 let inf: f32 = f32::INFINITY;
1264 let neg_inf: f32 = f32::NEG_INFINITY;
1265 assert!(!nan.is_infinite());
1266 assert!(inf.is_infinite());
1267 assert!(neg_inf.is_infinite());
1268 assert!(!0.0f32.is_infinite());
1269 assert!(!42.8f32.is_infinite());
1270 assert!(!(-109.2f32).is_infinite());
1274 fn test_is_finite() {
1275 let nan: f32 = f32::NAN;
1276 let inf: f32 = f32::INFINITY;
1277 let neg_inf: f32 = f32::NEG_INFINITY;
1278 assert!(!nan.is_finite());
1279 assert!(!inf.is_finite());
1280 assert!(!neg_inf.is_finite());
1281 assert!(0.0f32.is_finite());
1282 assert!(42.8f32.is_finite());
1283 assert!((-109.2f32).is_finite());
1287 fn test_is_normal() {
1288 let nan: f32 = f32::NAN;
1289 let inf: f32 = f32::INFINITY;
1290 let neg_inf: f32 = f32::NEG_INFINITY;
1291 let zero: f32 = 0.0f32;
1292 let neg_zero: f32 = -0.0;
1293 assert!(!nan.is_normal());
1294 assert!(!inf.is_normal());
1295 assert!(!neg_inf.is_normal());
1296 assert!(!zero.is_normal());
1297 assert!(!neg_zero.is_normal());
1298 assert!(1f32.is_normal());
1299 assert!(1e-37f32.is_normal());
1300 assert!(!1e-38f32.is_normal());
1304 fn test_classify() {
1305 let nan: f32 = f32::NAN;
1306 let inf: f32 = f32::INFINITY;
1307 let neg_inf: f32 = f32::NEG_INFINITY;
1308 let zero: f32 = 0.0f32;
1309 let neg_zero: f32 = -0.0;
1310 assert_eq!(nan.classify(), Fp::Nan);
1311 assert_eq!(inf.classify(), Fp::Infinite);
1312 assert_eq!(neg_inf.classify(), Fp::Infinite);
1313 assert_eq!(zero.classify(), Fp::Zero);
1314 assert_eq!(neg_zero.classify(), Fp::Zero);
1315 assert_eq!(1f32.classify(), Fp::Normal);
1316 assert_eq!(1e-37f32.classify(), Fp::Normal);
1317 assert_eq!(1e-38f32.classify(), Fp::Subnormal);
1322 assert_approx_eq!(1.0f32.floor(), 1.0f32);
1323 assert_approx_eq!(1.3f32.floor(), 1.0f32);
1324 assert_approx_eq!(1.5f32.floor(), 1.0f32);
1325 assert_approx_eq!(1.7f32.floor(), 1.0f32);
1326 assert_approx_eq!(0.0f32.floor(), 0.0f32);
1327 assert_approx_eq!((-0.0f32).floor(), -0.0f32);
1328 assert_approx_eq!((-1.0f32).floor(), -1.0f32);
1329 assert_approx_eq!((-1.3f32).floor(), -2.0f32);
1330 assert_approx_eq!((-1.5f32).floor(), -2.0f32);
1331 assert_approx_eq!((-1.7f32).floor(), -2.0f32);
1336 assert_approx_eq!(1.0f32.ceil(), 1.0f32);
1337 assert_approx_eq!(1.3f32.ceil(), 2.0f32);
1338 assert_approx_eq!(1.5f32.ceil(), 2.0f32);
1339 assert_approx_eq!(1.7f32.ceil(), 2.0f32);
1340 assert_approx_eq!(0.0f32.ceil(), 0.0f32);
1341 assert_approx_eq!((-0.0f32).ceil(), -0.0f32);
1342 assert_approx_eq!((-1.0f32).ceil(), -1.0f32);
1343 assert_approx_eq!((-1.3f32).ceil(), -1.0f32);
1344 assert_approx_eq!((-1.5f32).ceil(), -1.0f32);
1345 assert_approx_eq!((-1.7f32).ceil(), -1.0f32);
1350 assert_approx_eq!(1.0f32.round(), 1.0f32);
1351 assert_approx_eq!(1.3f32.round(), 1.0f32);
1352 assert_approx_eq!(1.5f32.round(), 2.0f32);
1353 assert_approx_eq!(1.7f32.round(), 2.0f32);
1354 assert_approx_eq!(0.0f32.round(), 0.0f32);
1355 assert_approx_eq!((-0.0f32).round(), -0.0f32);
1356 assert_approx_eq!((-1.0f32).round(), -1.0f32);
1357 assert_approx_eq!((-1.3f32).round(), -1.0f32);
1358 assert_approx_eq!((-1.5f32).round(), -2.0f32);
1359 assert_approx_eq!((-1.7f32).round(), -2.0f32);
1364 assert_approx_eq!(1.0f32.trunc(), 1.0f32);
1365 assert_approx_eq!(1.3f32.trunc(), 1.0f32);
1366 assert_approx_eq!(1.5f32.trunc(), 1.0f32);
1367 assert_approx_eq!(1.7f32.trunc(), 1.0f32);
1368 assert_approx_eq!(0.0f32.trunc(), 0.0f32);
1369 assert_approx_eq!((-0.0f32).trunc(), -0.0f32);
1370 assert_approx_eq!((-1.0f32).trunc(), -1.0f32);
1371 assert_approx_eq!((-1.3f32).trunc(), -1.0f32);
1372 assert_approx_eq!((-1.5f32).trunc(), -1.0f32);
1373 assert_approx_eq!((-1.7f32).trunc(), -1.0f32);
1378 assert_approx_eq!(1.0f32.fract(), 0.0f32);
1379 assert_approx_eq!(1.3f32.fract(), 0.3f32);
1380 assert_approx_eq!(1.5f32.fract(), 0.5f32);
1381 assert_approx_eq!(1.7f32.fract(), 0.7f32);
1382 assert_approx_eq!(0.0f32.fract(), 0.0f32);
1383 assert_approx_eq!((-0.0f32).fract(), -0.0f32);
1384 assert_approx_eq!((-1.0f32).fract(), -0.0f32);
1385 assert_approx_eq!((-1.3f32).fract(), -0.3f32);
1386 assert_approx_eq!((-1.5f32).fract(), -0.5f32);
1387 assert_approx_eq!((-1.7f32).fract(), -0.7f32);
1392 assert_eq!(INFINITY.abs(), INFINITY);
1393 assert_eq!(1f32.abs(), 1f32);
1394 assert_eq!(0f32.abs(), 0f32);
1395 assert_eq!((-0f32).abs(), 0f32);
1396 assert_eq!((-1f32).abs(), 1f32);
1397 assert_eq!(NEG_INFINITY.abs(), INFINITY);
1398 assert_eq!((1f32/NEG_INFINITY).abs(), 0f32);
1399 assert!(NAN.abs().is_nan());
1404 assert_eq!(INFINITY.signum(), 1f32);
1405 assert_eq!(1f32.signum(), 1f32);
1406 assert_eq!(0f32.signum(), 1f32);
1407 assert_eq!((-0f32).signum(), -1f32);
1408 assert_eq!((-1f32).signum(), -1f32);
1409 assert_eq!(NEG_INFINITY.signum(), -1f32);
1410 assert_eq!((1f32/NEG_INFINITY).signum(), -1f32);
1411 assert!(NAN.signum().is_nan());
1415 fn test_is_sign_positive() {
1416 assert!(INFINITY.is_sign_positive());
1417 assert!(1f32.is_sign_positive());
1418 assert!(0f32.is_sign_positive());
1419 assert!(!(-0f32).is_sign_positive());
1420 assert!(!(-1f32).is_sign_positive());
1421 assert!(!NEG_INFINITY.is_sign_positive());
1422 assert!(!(1f32/NEG_INFINITY).is_sign_positive());
1423 assert!(NAN.is_sign_positive());
1424 assert!(!(-NAN).is_sign_positive());
1428 fn test_is_sign_negative() {
1429 assert!(!INFINITY.is_sign_negative());
1430 assert!(!1f32.is_sign_negative());
1431 assert!(!0f32.is_sign_negative());
1432 assert!((-0f32).is_sign_negative());
1433 assert!((-1f32).is_sign_negative());
1434 assert!(NEG_INFINITY.is_sign_negative());
1435 assert!((1f32/NEG_INFINITY).is_sign_negative());
1436 assert!(!NAN.is_sign_negative());
1437 assert!((-NAN).is_sign_negative());
1442 let nan: f32 = f32::NAN;
1443 let inf: f32 = f32::INFINITY;
1444 let neg_inf: f32 = f32::NEG_INFINITY;
1445 assert_approx_eq!(12.3f32.mul_add(4.5, 6.7), 62.05);
1446 assert_approx_eq!((-12.3f32).mul_add(-4.5, -6.7), 48.65);
1447 assert_approx_eq!(0.0f32.mul_add(8.9, 1.2), 1.2);
1448 assert_approx_eq!(3.4f32.mul_add(-0.0, 5.6), 5.6);
1449 assert!(nan.mul_add(7.8, 9.0).is_nan());
1450 assert_eq!(inf.mul_add(7.8, 9.0), inf);
1451 assert_eq!(neg_inf.mul_add(7.8, 9.0), neg_inf);
1452 assert_eq!(8.9f32.mul_add(inf, 3.2), inf);
1453 assert_eq!((-3.2f32).mul_add(2.4, neg_inf), neg_inf);
1458 let nan: f32 = f32::NAN;
1459 let inf: f32 = f32::INFINITY;
1460 let neg_inf: f32 = f32::NEG_INFINITY;
1461 assert_eq!(1.0f32.recip(), 1.0);
1462 assert_eq!(2.0f32.recip(), 0.5);
1463 assert_eq!((-0.4f32).recip(), -2.5);
1464 assert_eq!(0.0f32.recip(), inf);
1465 assert!(nan.recip().is_nan());
1466 assert_eq!(inf.recip(), 0.0);
1467 assert_eq!(neg_inf.recip(), 0.0);
1472 let nan: f32 = f32::NAN;
1473 let inf: f32 = f32::INFINITY;
1474 let neg_inf: f32 = f32::NEG_INFINITY;
1475 assert_eq!(1.0f32.powi(1), 1.0);
1476 assert_approx_eq!((-3.1f32).powi(2), 9.61);
1477 assert_approx_eq!(5.9f32.powi(-2), 0.028727);
1478 assert_eq!(8.3f32.powi(0), 1.0);
1479 assert!(nan.powi(2).is_nan());
1480 assert_eq!(inf.powi(3), inf);
1481 assert_eq!(neg_inf.powi(2), inf);
1486 let nan: f32 = f32::NAN;
1487 let inf: f32 = f32::INFINITY;
1488 let neg_inf: f32 = f32::NEG_INFINITY;
1489 assert_eq!(1.0f32.powf(1.0), 1.0);
1490 assert_approx_eq!(3.4f32.powf(4.5), 246.408218);
1491 assert_approx_eq!(2.7f32.powf(-3.2), 0.041652);
1492 assert_approx_eq!((-3.1f32).powf(2.0), 9.61);
1493 assert_approx_eq!(5.9f32.powf(-2.0), 0.028727);
1494 assert_eq!(8.3f32.powf(0.0), 1.0);
1495 assert!(nan.powf(2.0).is_nan());
1496 assert_eq!(inf.powf(2.0), inf);
1497 assert_eq!(neg_inf.powf(3.0), neg_inf);
1501 fn test_sqrt_domain() {
1502 assert!(NAN.sqrt().is_nan());
1503 assert!(NEG_INFINITY.sqrt().is_nan());
1504 assert!((-1.0f32).sqrt().is_nan());
1505 assert_eq!((-0.0f32).sqrt(), -0.0);
1506 assert_eq!(0.0f32.sqrt(), 0.0);
1507 assert_eq!(1.0f32.sqrt(), 1.0);
1508 assert_eq!(INFINITY.sqrt(), INFINITY);
1513 assert_eq!(1.0, 0.0f32.exp());
1514 assert_approx_eq!(2.718282, 1.0f32.exp());
1515 assert_approx_eq!(148.413162, 5.0f32.exp());
1517 let inf: f32 = f32::INFINITY;
1518 let neg_inf: f32 = f32::NEG_INFINITY;
1519 let nan: f32 = f32::NAN;
1520 assert_eq!(inf, inf.exp());
1521 assert_eq!(0.0, neg_inf.exp());
1522 assert!(nan.exp().is_nan());
1527 assert_eq!(32.0, 5.0f32.exp2());
1528 assert_eq!(1.0, 0.0f32.exp2());
1530 let inf: f32 = f32::INFINITY;
1531 let neg_inf: f32 = f32::NEG_INFINITY;
1532 let nan: f32 = f32::NAN;
1533 assert_eq!(inf, inf.exp2());
1534 assert_eq!(0.0, neg_inf.exp2());
1535 assert!(nan.exp2().is_nan());
1540 let nan: f32 = f32::NAN;
1541 let inf: f32 = f32::INFINITY;
1542 let neg_inf: f32 = f32::NEG_INFINITY;
1543 assert_approx_eq!(1.0f32.exp().ln(), 1.0);
1544 assert!(nan.ln().is_nan());
1545 assert_eq!(inf.ln(), inf);
1546 assert!(neg_inf.ln().is_nan());
1547 assert!((-2.3f32).ln().is_nan());
1548 assert_eq!((-0.0f32).ln(), neg_inf);
1549 assert_eq!(0.0f32.ln(), neg_inf);
1550 assert_approx_eq!(4.0f32.ln(), 1.386294);
1555 let nan: f32 = f32::NAN;
1556 let inf: f32 = f32::INFINITY;
1557 let neg_inf: f32 = f32::NEG_INFINITY;
1558 assert_eq!(10.0f32.log(10.0), 1.0);
1559 assert_approx_eq!(2.3f32.log(3.5), 0.664858);
1560 assert_eq!(1.0f32.exp().log(1.0f32.exp()), 1.0);
1561 assert!(1.0f32.log(1.0).is_nan());
1562 assert!(1.0f32.log(-13.9).is_nan());
1563 assert!(nan.log(2.3).is_nan());
1564 assert_eq!(inf.log(10.0), inf);
1565 assert!(neg_inf.log(8.8).is_nan());
1566 assert!((-2.3f32).log(0.1).is_nan());
1567 assert_eq!((-0.0f32).log(2.0), neg_inf);
1568 assert_eq!(0.0f32.log(7.0), neg_inf);
1573 let nan: f32 = f32::NAN;
1574 let inf: f32 = f32::INFINITY;
1575 let neg_inf: f32 = f32::NEG_INFINITY;
1576 assert_approx_eq!(10.0f32.log2(), 3.321928);
1577 assert_approx_eq!(2.3f32.log2(), 1.201634);
1578 assert_approx_eq!(1.0f32.exp().log2(), 1.442695);
1579 assert!(nan.log2().is_nan());
1580 assert_eq!(inf.log2(), inf);
1581 assert!(neg_inf.log2().is_nan());
1582 assert!((-2.3f32).log2().is_nan());
1583 assert_eq!((-0.0f32).log2(), neg_inf);
1584 assert_eq!(0.0f32.log2(), neg_inf);
1589 let nan: f32 = f32::NAN;
1590 let inf: f32 = f32::INFINITY;
1591 let neg_inf: f32 = f32::NEG_INFINITY;
1592 assert_eq!(10.0f32.log10(), 1.0);
1593 assert_approx_eq!(2.3f32.log10(), 0.361728);
1594 assert_approx_eq!(1.0f32.exp().log10(), 0.434294);
1595 assert_eq!(1.0f32.log10(), 0.0);
1596 assert!(nan.log10().is_nan());
1597 assert_eq!(inf.log10(), inf);
1598 assert!(neg_inf.log10().is_nan());
1599 assert!((-2.3f32).log10().is_nan());
1600 assert_eq!((-0.0f32).log10(), neg_inf);
1601 assert_eq!(0.0f32.log10(), neg_inf);
1605 fn test_to_degrees() {
1606 let pi: f32 = consts::PI;
1607 let nan: f32 = f32::NAN;
1608 let inf: f32 = f32::INFINITY;
1609 let neg_inf: f32 = f32::NEG_INFINITY;
1610 assert_eq!(0.0f32.to_degrees(), 0.0);
1611 assert_approx_eq!((-5.8f32).to_degrees(), -332.315521);
1612 assert_eq!(pi.to_degrees(), 180.0);
1613 assert!(nan.to_degrees().is_nan());
1614 assert_eq!(inf.to_degrees(), inf);
1615 assert_eq!(neg_inf.to_degrees(), neg_inf);
1619 fn test_to_radians() {
1620 let pi: f32 = consts::PI;
1621 let nan: f32 = f32::NAN;
1622 let inf: f32 = f32::INFINITY;
1623 let neg_inf: f32 = f32::NEG_INFINITY;
1624 assert_eq!(0.0f32.to_radians(), 0.0);
1625 assert_approx_eq!(154.6f32.to_radians(), 2.698279);
1626 assert_approx_eq!((-332.31f32).to_radians(), -5.799903);
1627 assert_eq!(180.0f32.to_radians(), pi);
1628 assert!(nan.to_radians().is_nan());
1629 assert_eq!(inf.to_radians(), inf);
1630 assert_eq!(neg_inf.to_radians(), neg_inf);
1635 assert_eq!(0.0f32.asinh(), 0.0f32);
1636 assert_eq!((-0.0f32).asinh(), -0.0f32);
1638 let inf: f32 = f32::INFINITY;
1639 let neg_inf: f32 = f32::NEG_INFINITY;
1640 let nan: f32 = f32::NAN;
1641 assert_eq!(inf.asinh(), inf);
1642 assert_eq!(neg_inf.asinh(), neg_inf);
1643 assert!(nan.asinh().is_nan());
1644 assert_approx_eq!(2.0f32.asinh(), 1.443635475178810342493276740273105f32);
1645 assert_approx_eq!((-2.0f32).asinh(), -1.443635475178810342493276740273105f32);
1650 assert_eq!(1.0f32.acosh(), 0.0f32);
1651 assert!(0.999f32.acosh().is_nan());
1653 let inf: f32 = f32::INFINITY;
1654 let neg_inf: f32 = f32::NEG_INFINITY;
1655 let nan: f32 = f32::NAN;
1656 assert_eq!(inf.acosh(), inf);
1657 assert!(neg_inf.acosh().is_nan());
1658 assert!(nan.acosh().is_nan());
1659 assert_approx_eq!(2.0f32.acosh(), 1.31695789692481670862504634730796844f32);
1660 assert_approx_eq!(3.0f32.acosh(), 1.76274717403908605046521864995958461f32);
1665 assert_eq!(0.0f32.atanh(), 0.0f32);
1666 assert_eq!((-0.0f32).atanh(), -0.0f32);
1668 let inf32: f32 = f32::INFINITY;
1669 let neg_inf32: f32 = f32::NEG_INFINITY;
1670 assert_eq!(1.0f32.atanh(), inf32);
1671 assert_eq!((-1.0f32).atanh(), neg_inf32);
1673 assert!(2f64.atanh().atanh().is_nan());
1674 assert!((-2f64).atanh().atanh().is_nan());
1676 let inf64: f32 = f32::INFINITY;
1677 let neg_inf64: f32 = f32::NEG_INFINITY;
1678 let nan32: f32 = f32::NAN;
1679 assert!(inf64.atanh().is_nan());
1680 assert!(neg_inf64.atanh().is_nan());
1681 assert!(nan32.atanh().is_nan());
1683 assert_approx_eq!(0.5f32.atanh(), 0.54930614433405484569762261846126285f32);
1684 assert_approx_eq!((-0.5f32).atanh(), -0.54930614433405484569762261846126285f32);
1688 fn test_real_consts() {
1691 let pi: f32 = consts::PI;
1692 let frac_pi_2: f32 = consts::FRAC_PI_2;
1693 let frac_pi_3: f32 = consts::FRAC_PI_3;
1694 let frac_pi_4: f32 = consts::FRAC_PI_4;
1695 let frac_pi_6: f32 = consts::FRAC_PI_6;
1696 let frac_pi_8: f32 = consts::FRAC_PI_8;
1697 let frac_1_pi: f32 = consts::FRAC_1_PI;
1698 let frac_2_pi: f32 = consts::FRAC_2_PI;
1699 let frac_2_sqrtpi: f32 = consts::FRAC_2_SQRT_PI;
1700 let sqrt2: f32 = consts::SQRT_2;
1701 let frac_1_sqrt2: f32 = consts::FRAC_1_SQRT_2;
1702 let e: f32 = consts::E;
1703 let log2_e: f32 = consts::LOG2_E;
1704 let log10_e: f32 = consts::LOG10_E;
1705 let ln_2: f32 = consts::LN_2;
1706 let ln_10: f32 = consts::LN_10;
1708 assert_approx_eq!(frac_pi_2, pi / 2f32);
1709 assert_approx_eq!(frac_pi_3, pi / 3f32);
1710 assert_approx_eq!(frac_pi_4, pi / 4f32);
1711 assert_approx_eq!(frac_pi_6, pi / 6f32);
1712 assert_approx_eq!(frac_pi_8, pi / 8f32);
1713 assert_approx_eq!(frac_1_pi, 1f32 / pi);
1714 assert_approx_eq!(frac_2_pi, 2f32 / pi);
1715 assert_approx_eq!(frac_2_sqrtpi, 2f32 / pi.sqrt());
1716 assert_approx_eq!(sqrt2, 2f32.sqrt());
1717 assert_approx_eq!(frac_1_sqrt2, 1f32 / 2f32.sqrt());
1718 assert_approx_eq!(log2_e, e.log2());
1719 assert_approx_eq!(log10_e, e.log10());
1720 assert_approx_eq!(ln_2, 2f32.ln());
1721 assert_approx_eq!(ln_10, 10f32.ln());
1725 fn test_float_bits_conv() {
1726 assert_eq!((1f32).to_bits(), 0x3f800000);
1727 assert_eq!((12.5f32).to_bits(), 0x41480000);
1728 assert_eq!((1337f32).to_bits(), 0x44a72000);
1729 assert_eq!((-14.25f32).to_bits(), 0xc1640000);
1730 assert_approx_eq!(f32::from_bits(0x3f800000), 1.0);
1731 assert_approx_eq!(f32::from_bits(0x41480000), 12.5);
1732 assert_approx_eq!(f32::from_bits(0x44a72000), 1337.0);
1733 assert_approx_eq!(f32::from_bits(0xc1640000), -14.25);
1736 fn test_snan_masking() {
1737 let snan: u32 = 0x7F801337;
1738 const PAYLOAD_MASK: u32 = 0x003FFFFF;
1739 const QNAN_MASK: u32 = 0x00400000;
1740 let nan_masked_fl = f32::from_bits(snan);
1741 let nan_masked = nan_masked_fl.to_bits();
1742 // Ensure that signaling NaNs don't stay the same
1743 assert_ne!(nan_masked, snan);
1744 // Ensure that we have a quiet NaN
1745 assert_ne!(nan_masked & QNAN_MASK, 0);
1746 assert!(nan_masked_fl.is_nan());
1747 // Ensure the payload wasn't touched during conversion
1748 assert_eq!(nan_masked & PAYLOAD_MASK, snan & PAYLOAD_MASK);