M-Labs/nalgebra
3
0
Fork 1
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Fix for [a,ca]min/max methods.

Browse Source 
Panic on empty matrices, propagate NaN, fix of wrong results, added doc tests
This commit is contained in:
Fabian Löschner 2019-08-10 16:18:33 +02:00 committed by Sébastien Crozet
parent bedb5dc963
commit 0f0b9bcca1
1 changed files with 118 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

136
src/base/ops.rs
View File

@ -1,5 +1,5 @@
use num::{One, Signed, Zero};
use std::cmp::PartialOrd;
use std::cmp::{PartialOrd, Ordering};
use std::iter;
use std::ops::{
Add, AddAssign, Div, DivAssign, Index, IndexMut, Mul, MulAssign, Neg, Sub, SubAssign,
@ -868,60 +868,160 @@ where
impl<N: Scalar, R: Dim, C: Dim, S: Storage<N, R, C>> Matrix<N, R, C, S> {
#[inline(always)]
fn xcmp<N2>(&self, abs: impl Fn(N) -> N2, cmp: impl Fn(N2, N2) -> bool) -> N2
fn xcmp<N2>(&self, abs: impl Fn(N) -> N2, ordering: Ordering) -> N2
where N2: Scalar + PartialOrd + Zero {
let mut max = N2::zero();
assert!(self.len() > 0, "Empty matrix supplied to min/max function.");
let mut iter = self.iter();
let mut max = abs(iter.next().cloned().unwrap());
for e in self.iter() {
for e in iter {
let ae = abs(*e);
if cmp(ae, max) {
max = ae;
if let Some(ae_ordering) = ae.partial_cmp(&max) {
if ae_ordering == ordering {
max = ae;
}
} else {
return ae;
}
}
max
}
/// Returns the absolute value of the component with the largest absolute value.
/// Returns the absolute value of the component with the largest absolute value. Propagates NaN.
/// # Example
/// ```
/// # use nalgebra::Vector3;
/// assert_eq!(Vector3::new(-1.0, 2.0, 3.0).amax(), 3.0);
/// assert_eq!(Vector3::new(-1.0, -2.0, -3.0).amax(), 3.0);
/// assert!(Vector3::new(1.0, std::f64::NAN, 3.0).amax().is_nan());
/// ```
///
/// # Panics
/// Panics if the matrix is empty:
/// ```should_panic
/// # use nalgebra::DMatrix;
/// let min = DMatrix::<f64>::zeros(0,1).amax(); // panics!
/// ```
#[inline]
pub fn amax(&self) -> N
where N: PartialOrd + Signed {
self.xcmp(|e| e.abs(), |a, b| a > b)
self.xcmp(|e| e.abs(), Ordering::Greater)
}
/// Returns the the 1-norm of the complex component with the largest 1-norm.
/// Returns the the 1-norm of the complex component with the largest 1-norm. Propagates NaN.
/// # Example
/// ```
/// # use nalgebra::{Vector3, Complex};
/// assert_eq!(Vector3::new(
/// Complex::new(-3.0, -2.0),
/// Complex::new(1.0, 2.0),
/// Complex::new(1.0, 3.0)).camax(), 5.0);
/// assert!(Vector3::new(
/// Complex::new(-3.0, -2.0),
/// Complex::new(1.0, std::f64::NAN),
/// Complex::new(1.0, 3.0)).camax().is_nan());
/// ```
///
/// # Panics
/// Panics if the matrix is empty:
/// ```should_panic
/// # use nalgebra::{DMatrix, Complex};
/// let min = DMatrix::<Complex<f64>>::zeros(0,1).camax(); // panics!
/// ```
#[inline]
pub fn camax(&self) -> N::RealField
where N: ComplexField {
self.xcmp(|e| e.norm1(), |a, b| a > b)
self.xcmp(|e| e.norm1(), Ordering::Greater)
}
/// Returns the component with the largest value.
/// Returns the component with the largest value. Propagates NaN.
/// # Example
/// ```
/// # use nalgebra::Vector3;
/// assert_eq!(Vector3::new(-1.0, 2.0, 3.0).max(), 3.0);
/// assert_eq!(Vector3::new(-1.0, -2.0, -3.0).max(), -1.0);
/// assert!(Vector3::new(1.0, std::f64::NAN, 3.0).max().is_nan());
/// ```
///
/// # Panics
/// Panics if the matrix is empty:
/// ```should_panic
/// # use nalgebra::DMatrix;
/// let min = DMatrix::<f64>::zeros(0,1).max(); // panics!
/// ```
#[inline]
pub fn max(&self) -> N
where N: PartialOrd + Signed {
self.xcmp(|e| e, |a, b| a > b)
self.xcmp(|e| e, Ordering::Greater)
}
/// Returns the absolute value of the component with the smallest absolute value.
/// Returns the absolute value of the component with the smallest absolute value. Propagates NaN.
/// # Example
/// ```
/// # use nalgebra::Vector3;
/// assert_eq!(Vector3::new(-1.0, 2.0, -3.0).amin(), 1.0);
/// assert_eq!(Vector3::new(10.0, 2.0, 30.0).amin(), 2.0);
/// assert!(Vector3::new(-1.0, std::f64::NAN, 3.0).amin().is_nan());
/// ```
///
/// # Panics
/// Panics if the matrix is empty:
/// ```should_panic
/// # use nalgebra::DMatrix;
/// let min = DMatrix::<f64>::zeros(0,1).amin(); // panics!
/// ```
#[inline]
pub fn amin(&self) -> N
where N: PartialOrd + Signed {
self.xcmp(|e| e.abs(), |a, b| a < b)
self.xcmp(|e| e.abs(), Ordering::Less)
}
/// Returns the the 1-norm of the complex component with the smallest 1-norm.
/// Returns the the 1-norm of the complex component with the smallest 1-norm. Propagates NaN.
/// # Example
/// ```
/// # use nalgebra::{Vector3, Complex};
/// assert_eq!(Vector3::new(
/// Complex::new(-3.0, -2.0),
/// Complex::new(1.0, 2.0),
/// Complex::new(1.0, 3.0)).camin(), 3.0);
/// assert!(Vector3::new(
/// Complex::new(-3.0, -2.0),
/// Complex::new(1.0, std::f64::NAN),
/// Complex::new(1.0, 3.0)).camin().is_nan());
/// ```
///
/// # Panics
/// Panics if the matrix is empty:
/// ```should_panic
/// # use nalgebra::{DMatrix, Complex};
/// let min = DMatrix::<Complex<f64>>::zeros(0,1).camin(); // panics!
/// ```
#[inline]
pub fn camin(&self) -> N::RealField
where N: ComplexField {
self.xcmp(|e| e.norm1(), |a, b| a < b)
self.xcmp(|e| e.norm1(), Ordering::Less)
}
/// Returns the component with the smallest value.
/// Returns the component with the smallest value. Propagates NaN.
/// # Example
/// ```
/// # use nalgebra::Vector3;
/// assert_eq!(Vector3::new(-1.0, 2.0, 3.0).min(), -1.0);
/// assert_eq!(Vector3::new(1.0, 2.0, 3.0).min(), 1.0);
/// assert!(Vector3::new(1.0, std::f64::NAN, 3.0).min().is_nan());
/// ```
///
/// # Panics
/// Panics if the matrix is empty:
/// ```should_panic
/// # use nalgebra::DMatrix;
/// let min = DMatrix::<f64>::zeros(0,1).min(); // panics!
/// ```
#[inline]
pub fn min(&self) -> N
where N: PartialOrd + Signed {
self.xcmp(|e| e, |a, b| a < b)
self.xcmp(|e| e, Ordering::Less)
}
}