Struct statrs::distribution::Weibull
source · [−]pub struct Weibull { /* private fields */ }
Expand description
Implements the Weibull distribution
Examples
use statrs::distribution::{Weibull, Continuous};
use statrs::statistics::Distribution;
use statrs::prec;
let n = Weibull::new(10.0, 1.0).unwrap();
assert!(prec::almost_eq(n.mean().unwrap(),
0.95135076986687318362924871772654021925505786260884, 1e-15));
assert_eq!(n.pdf(1.0), 3.6787944117144232159552377016146086744581113103177);
Implementations
sourceimpl Weibull
impl Weibull
sourcepub fn new(shape: f64, scale: f64) -> Result<Weibull>
pub fn new(shape: f64, scale: f64) -> Result<Weibull>
Constructs a new weibull distribution with a shape (k) of shape
and a scale (λ) of scale
Errors
Returns an error if shape
or scale
are NaN
.
Returns an error if shape <= 0.0
or scale <= 0.0
Examples
use statrs::distribution::Weibull;
let mut result = Weibull::new(10.0, 1.0);
assert!(result.is_ok());
result = Weibull::new(0.0, 0.0);
assert!(result.is_err());
Trait Implementations
sourceimpl Continuous<f64, f64> for Weibull
impl Continuous<f64, f64> for Weibull
sourceimpl ContinuousCDF<f64, f64> for Weibull
impl ContinuousCDF<f64, f64> for Weibull
sourcefn cdf(&self, x: f64) -> f64
fn cdf(&self, x: f64) -> f64
Calculates the cumulative distribution function for the weibull
distribution at x
Formula
1 - e^-((x/λ)^k)
where k
is the shape and λ
is the scale
sourcefn sf(&self, x: f64) -> f64
fn sf(&self, x: f64) -> f64
Calculates the survival function for the weibull
distribution at x
Formula
e^-((x/λ)^k)
where k
is the shape and λ
is the scale
sourcefn inverse_cdf(&self, p: T) -> K
fn inverse_cdf(&self, p: T) -> K
Due to issues with rounding and floating-point accuracy the default
implementation may be ill-behaved.
Specialized inverse cdfs should be used whenever possible.
Performs a binary search on the domain of cdf
to obtain an approximation
of F^-1(p) := inf { x | F(x) >= p }
. Needless to say, performance may
may be lacking. Read more
sourceimpl Distribution<f64> for Weibull
impl Distribution<f64> for Weibull
sourcefn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> f64
fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> f64
Generate a random value of T
, using rng
as the source of randomness.
sourcefn sample_iter<R>(self, rng: R) -> DistIter<Self, R, T> where
R: Rng,
fn sample_iter<R>(self, rng: R) -> DistIter<Self, R, T> where
R: Rng,
Create an iterator that generates random values of T
, using rng
as
the source of randomness. Read more
sourceimpl Distribution<f64> for Weibull
impl Distribution<f64> for Weibull
sourcefn mean(&self) -> Option<f64>
fn mean(&self) -> Option<f64>
Returns the mean of the weibull distribution
Formula
λΓ(1 + 1 / k)
where k
is the shape, λ
is the scale, and Γ
is
the gamma function
sourcefn variance(&self) -> Option<f64>
fn variance(&self) -> Option<f64>
Returns the variance of the weibull distribution
Formula
λ^2 * (Γ(1 + 2 / k) - Γ(1 + 1 / k)^2)
where k
is the shape, λ
is the scale, and Γ
is
the gamma function
sourcefn entropy(&self) -> Option<f64>
fn entropy(&self) -> Option<f64>
Returns the entropy of the weibull distribution
Formula
γ(1 - 1 / k) + ln(λ / k) + 1
where k
is the shape, λ
is the scale, and γ
is
the Euler-Mascheroni constant
sourceimpl PartialEq<Weibull> for Weibull
impl PartialEq<Weibull> for Weibull
impl Copy for Weibull
impl StructuralPartialEq for Weibull
Auto Trait Implementations
impl RefUnwindSafe for Weibull
impl Send for Weibull
impl Sync for Weibull
impl Unpin for Weibull
impl UnwindSafe for Weibull
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
impl<SS, SP> SupersetOf<SS> for SP where
SS: SubsetOf<SP>,
impl<SS, SP> SupersetOf<SS> for SP where
SS: SubsetOf<SP>,
fn to_subset(&self) -> Option<SS>
fn to_subset(&self) -> Option<SS>
The inverse inclusion map: attempts to construct self
from the equivalent element of its
superset. Read more
fn is_in_subset(&self) -> bool
fn is_in_subset(&self) -> bool
Checks if self
is actually part of its subset T
(and can be converted to it).
fn to_subset_unchecked(&self) -> SS
fn to_subset_unchecked(&self) -> SS
Use with care! Same as self.to_subset
but without any property checks. Always succeeds.
fn from_subset(element: &SS) -> SP
fn from_subset(element: &SS) -> SP
The inclusion map: converts self
to the equivalent element of its superset.