OpenE2K/rust
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Rollup merge of #77099 - tspiteri:exp_m1-examples, r=m-ou-se

Browse Source 
make exp_m1 and ln_1p examples more representative of use

With this PR, the examples for `exp_m1` would fail if `x.exp() - 1.0` is used instead of `x.exp_m1()`, and the examples for `ln_1p` would fail if `(x + 1.0).ln()` is used instead of `x.ln_1p()`.
This commit is contained in:
Mara Bos 2020-10-31 09:49:32 +01:00 committed by GitHub
commit 4ebd5536b4
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 20 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
library/std/src/f32.rs
View File

@ -719,12 +719,13 @@ impl f32 {
/// # Examples
///
/// ```
/// let x = 6.0f32;
/// let x = 1e-8_f32;
///
/// // e^(ln(6)) - 1
/// let abs_difference = (x.ln().exp_m1() - 5.0).abs();
/// // for very small x, e^x is approximately 1 + x + x^2 / 2
/// let approx = x + x * x / 2.0;
/// let abs_difference = (x.exp_m1() - approx).abs();
///
/// assert!(abs_difference <= f32::EPSILON);
/// assert!(abs_difference < 1e-10);
/// ```
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
@ -739,12 +740,13 @@ impl f32 {
/// # Examples
///
/// ```
/// let x = std::f32::consts::E - 1.0;
/// let x = 1e-8_f32;
///
/// // ln(1 + (e - 1)) == ln(e) == 1
/// let abs_difference = (x.ln_1p() - 1.0).abs();
/// // for very small x, ln(1 + x) is approximately x - x^2 / 2
/// let approx = x - x * x / 2.0;
/// let abs_difference = (x.ln_1p() - approx).abs();
///
/// assert!(abs_difference <= f32::EPSILON);
/// assert!(abs_difference < 1e-10);
/// ```
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]

18
library/std/src/f64.rs
View File

@ -721,12 +721,13 @@ impl f64 {
/// # Examples
///
/// ```
/// let x = 7.0_f64;
/// let x = 1e-16_f64;
///
/// // e^(ln(7)) - 1
/// let abs_difference = (x.ln().exp_m1() - 6.0).abs();
/// // for very small x, e^x is approximately 1 + x + x^2 / 2
/// let approx = x + x * x / 2.0;
/// let abs_difference = (x.exp_m1() - approx).abs();
///
/// assert!(abs_difference < 1e-10);
/// assert!(abs_difference < 1e-20);
/// ```
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]
@ -741,12 +742,13 @@ impl f64 {
/// # Examples
///
/// ```
/// let x = std::f64::consts::E - 1.0;
/// let x = 1e-16_f64;
///
/// // ln(1 + (e - 1)) == ln(e) == 1
/// let abs_difference = (x.ln_1p() - 1.0).abs();
/// // for very small x, ln(1 + x) is approximately x - x^2 / 2
/// let approx = x - x * x / 2.0;
/// let abs_difference = (x.ln_1p() - approx).abs();
///
/// assert!(abs_difference < 1e-10);
/// assert!(abs_difference < 1e-20);
/// ```
#[must_use = "method returns a new number and does not mutate the original value"]
#[stable(feature = "rust1", since = "1.0.0")]