use crate::{DistributionError, MultinominalError, RandomVariable};
#[derive(Clone, Debug, PartialEq)]
pub struct MultinomialParams {
n: u64,
p: f64,
}
impl MultinomialParams {
pub fn new(n: u64, p: f64) -> Result<Self, DistributionError> {
if p < 0.0 || 1.0 < p {
return Err(DistributionError::InvalidParameters(
MultinominalError::PMustBeProbability.into(),
));
}
Ok(Self { n, p })
}
pub fn n(&self) -> u64 {
self.n
}
pub fn p(&self) -> f64 {
self.p
}
}
impl RandomVariable for MultinomialParams {
type RestoreInfo = u64;
fn transform_vec(&self) -> (Vec<f64>, Self::RestoreInfo) {
(vec![self.p], self.n)
}
fn len(&self) -> usize {
2usize
}
fn restore(v: &[f64], info: &Self::RestoreInfo) -> Result<Self, DistributionError> {
if v.len() != 1 {
return Err(DistributionError::InvalidRestoreVector);
}
MultinomialParams::new(*info, v[1])
}
}