pub struct Chi { /* private fields */ }
Expand description
Implements the Chi
distribution
use statrs::distribution::{Chi, Continuous};
use statrs::statistics::Distribution;
use statrs::prec;
let n = Chi::new(2.0).unwrap();
assert!(prec::almost_eq(n.mean().unwrap(), 1.25331413731550025121, 1e-14));
assert!(prec::almost_eq(n.pdf(1.0), 0.60653065971263342360, 1e-15));
Constructs a new chi distribution
with freedom degrees of freedom
Returns an error if freedom is NaN or
less than or equal to 0.0
use statrs::distribution::Chi;
let mut result = Chi::new(2.0);
assert!(result.is_ok());
result = Chi::new(0.0);
assert!(result.is_err());
Returns the degrees of freedom of
the chi distribution.
use statrs::distribution::Chi;
let n = Chi::new(2.0).unwrap();
assert_eq!(n.freedom(), 2.0);
Performs copy-assignment from source. Read more
Calculates the probability density function for the chi
distribution at x
(2^(1 - (k / 2)) * x^(k - 1) * e^(-x^2 / 2)) / Γ(k / 2)
where k is the degrees of freedom and Γ is the gamma function
Calculates the log probability density function for the chi distribution
at x
ln((2^(1 - (k / 2)) * x^(k - 1) * e^(-x^2 / 2)) / Γ(k / 2))
Calculates the cumulative distribution function for the chi
distribution at x.
where k is the degrees of freedom and P is
the regularized Gamma function
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
Formats the value using the given formatter. Read more
Generate a random value of T, using rng as the source of randomness.
Create an iterator that generates random values of T, using rng as
the source of randomness. Read more
Create a distribution of values of ‘S’ by mapping the output of Self
through the closure F Read more
Returns the mean of the chi distribution
Returns NaN if freedom is INF
sqrt2 * Γ((k + 1) / 2) / Γ(k / 2)
where k is degrees of freedom and Γ is the gamma function
Returns the variance of the chi distribution
Returns NaN if freedom is INF
where k is degrees of freedom and μ is the mean
of the distribution
Returns the entropy of the chi distribution
Returns None if freedom is INF
ln(Γ(k / 2)) + 0.5 * (k - ln2 - (k - 1) * ψ(k / 2))
where k is degrees of freedom, Γ is the gamma function,
and ψ is the digamma function
Returns the skewness of the chi distribution
Returns NaN if freedom is INF
where μ is the mean and σ the standard deviation
of the distribution
Returns the standard deviation, if it exists. Read more
Returns the maximum value in the domain of the chi distribution
representable by a double precision float
Returns the minimum value in the domain of the chi distribution
representable by a double precision float
Returns the mode for the chi distribution
If freedom < 1.0
where k is the degrees of freedom
This method tests for self and other values to be equal, and is used
by ==. Read more
This method tests for !=.
impl<T> Any for T where
T: 'static + ?Sized,
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more
impl<T, U> Into<U> for T where
U: From<T>,
Performance hack: Clone doesn’t get inlined for Copy types in debug mode, so make it inline anyway.
Tests if Self the same as the type T Read more
The inverse inclusion map: attempts to construct self from the equivalent element of its
superset. Read more
Checks if self is actually part of its subset T (and can be converted to it).
Use with care! Same as self.to_subset but without any property checks. Always succeeds.
The inclusion map: converts self to the equivalent element of its superset.
The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
🔬 This is a nightly-only experimental API. (toowned_clone_into)
Uses borrowed data to replace owned data, usually by cloning. Read more
The type returned in the event of a conversion error.
The type returned in the event of a conversion error.
