Add docs

Author: Schultzer

src/math/acos.rs

@@ -55,6 +55,11 @@ fn r(z: f64) -> f64 {
     p / q
 }
 
+/// Arccosine (f64)
+///
+/// Computes the inverse cosine (arc cosine) of the input value.
+/// Arguments must be in the range -1 to 1.
+/// Returns values in radians, in the range of 0 to pi.
 #[inline]
 #[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
 pub fn acos(x: f64) -> f64 {

src/math/acosf.rs

@@ -29,6 +29,11 @@ fn r(z: f32) -> f32 {
     p / q
 }
 
+/// Arccosine (f32)
+///
+/// Computes the inverse cosine (arc cosine) of the input value.
+/// Arguments must be in the range -1 to 1.
+/// Returns values in radians, in the range of 0 to pi.
 #[inline]
 #[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
 pub fn acosf(x: f32) -> f32 {

src/math/acosh.rs

@@ -2,7 +2,11 @@ use super::{log, log1p, sqrt};
 
 const LN2: f64 = 0.693147180559945309417232121458176568; /* 0x3fe62e42,  0xfefa39ef*/
 
-/* acosh(x) = log(x + sqrt(x*x-1)) */
+/// Inverse hyperbolic cosine (f64)
+///
+/// Calculates the inverse hyperbolic cosine of `x`.
+/// Is defined as `log(x + sqrt(x*x-1))`.
+/// `x` must be a number greater than or equal to 1.
 pub fn acosh(x: f64) -> f64 {
     let u = x.to_bits();
     let e = ((u >> 52) as usize) & 0x7ff;

src/math/acoshf.rs

@@ -2,7 +2,11 @@ use super::{log1pf, logf, sqrtf};
 
 const LN2: f32 = 0.693147180559945309417232121458176568;
 
-/* acosh(x) = log(x + sqrt(x*x-1)) */
+/// Inverse hyperbolic cosine (f32)
+///
+/// Calculates the inverse hyperbolic cosine of `x`.
+/// Is defined as `log(x + sqrt(x*x-1))`.
+/// `x` must be a number greater than or equal to 1.
 pub fn acoshf(x: f32) -> f32 {
     let u = x.to_bits();
     let a = u & 0x7fffffff;

src/math/asin.rs

@@ -62,6 +62,11 @@ fn comp_r(z: f64) -> f64 {
     p / q
 }
 
+/// Arcsine (f64)
+///
+/// Computes the inverse sine (arc sine) of the argument `x`.
+/// Arguments to asin must be in the range -1 to 1.
+/// Returns values in radians, in the range of -pi/2 to pi/2.
 #[inline]
 #[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
 pub fn asin(mut x: f64) -> f64 {

src/math/asinf.rs

@@ -31,6 +31,11 @@ fn r(z: f32) -> f32 {
     p / q
 }
 
+/// Arcsine (f32)
+///
+/// Computes the inverse sine (arc sine) of the argument `x`.
+/// Arguments to asin must be in the range -1 to 1.
+/// Returns values in radians, in the range of -pi/2 to pi/2.
 #[inline]
 #[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
 pub fn asinf(mut x: f32) -> f32 {

src/math/asinh.rs

@@ -3,6 +3,10 @@ use super::{log, log1p, sqrt};
 const LN2: f64 = 0.693147180559945309417232121458176568; /* 0x3fe62e42,  0xfefa39ef*/
 
 /* asinh(x) = sign(x)*log(|x|+sqrt(x*x+1)) ~= x - x^3/6 + o(x^5) */
+/// Inverse hyperbolic sine (f64)
+///
+/// Calculates the inverse hyperbolic sine of `x`.
+/// Is defined as `sgn(x)*log(|x|+sqrt(x*x+1))`.
 pub fn asinh(mut x: f64) -> f64 {
     let mut u = x.to_bits();
     let e = ((u >> 52) as usize) & 0x7ff;

src/math/asinhf.rs

@@ -3,6 +3,10 @@ use super::{log1pf, logf, sqrtf};
 const LN2: f32 = 0.693147180559945309417232121458176568;
 
 /* asinh(x) = sign(x)*log(|x|+sqrt(x*x+1)) ~= x - x^3/6 + o(x^5) */
+/// Inverse hyperbolic sine (f32)
+///
+/// Calculates the inverse hyperbolic sine of `x`.
+/// Is defined as `sgn(x)*log(|x|+sqrt(x*x+1))`.
 pub fn asinhf(mut x: f32) -> f32 {
     let u = x.to_bits();
     let i = u & 0x7fffffff;

src/math/atan.rs

@@ -60,6 +60,10 @@ const AT: [f64; 11] = [
     1.62858201153657823623e-02,  /* 0x3F90AD3A, 0xE322DA11 */
 ];
 
+/// Arctangent (f64)
+///
+/// Computes the inverse tangent (arc tangent) of the input value.
+/// Returns a value in radians, in the range of -pi/2 to pi/2.
 #[inline]
 #[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
 pub fn atan(x: f64) -> f64 {

src/math/atan2.rs

@@ -43,6 +43,11 @@ use super::fabs;
 const PI: f64 = 3.1415926535897931160E+00; /* 0x400921FB, 0x54442D18 */
 const PI_LO: f64 = 1.2246467991473531772E-16; /* 0x3CA1A626, 0x33145C07 */
 
+/// Arctangent of y/x (f64)
+///
+/// Computes the inverse tangent (arc tangent) of `y/x`.
+/// Produces the correct result even for angles near pi/2 or -pi/2 (that is, when `x` is near 0).
+/// Returns a value in radians, in the range of -pi to pi.
 #[inline]
 #[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
 pub fn atan2(y: f64, x: f64) -> f64 {