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Add methods to compute the products of a single matrix components/rows/columns

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This commit is contained in:
Sébastien Crozet 2021-10-06 10:44:46 +02:00
parent 2e9c8aef20
commit 97a79a994b
2 changed files with 129 additions and 7 deletions
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2
CHANGELOG.md
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@ -11,6 +11,8 @@ This project adheres to [Semantic Versioning](https://semver.org/).
- The conversion trait `From<Vec<T>>` and method `from_vec_storage` for `RowDVector`. See [#975](https://github.com/dimforge/nalgebra/issues/975)
- Added implementation of `From` and `Into` for converting between `nalgebra` types and types from
`glam 0.18`. These can be enabled by enabling the `convert-glam018` cargo features.
- Added the methods `Matrix::product`, `::row_product`, `::row_product_tr`, and `::column_product` to compute the
product of the components, rows, or columns, of a single matrix or vector.
## [0.29.0]
### Breaking changes

134
src/base/statistics.rs
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@ -1,8 +1,8 @@
use crate::allocator::Allocator;
use crate::storage::RawStorage;
use crate::{Const, DefaultAllocator, Dim, Matrix, OVector, RowOVector, Scalar, VectorSlice, U1};
use num::Zero;
use simba::scalar::{ClosedAdd, Field, SupersetOf};
use num::{One, Zero};
use simba::scalar::{ClosedAdd, ClosedMul, Field, SupersetOf};
use std::mem::MaybeUninit;
/// # Folding on columns and rows
@ -123,7 +123,9 @@ impl<T: Scalar, R: Dim, C: Dim, S: RawStorage<T, R, C>> Matrix<T, R, C, S> {
/// 4.0, 5.0, 6.0);
/// assert_eq!(m.row_sum(), RowVector3::new(5.0, 7.0, 9.0));
///
/// let mint = Matrix3x2::new(1,2,3,4,5,6);
/// let mint = Matrix3x2::new(1, 2,
/// 3, 4,
/// 5, 6);
/// assert_eq!(mint.row_sum(), RowVector2::new(9,12));
/// ```
#[inline]
@ -148,8 +150,10 @@ impl<T: Scalar, R: Dim, C: Dim, S: RawStorage<T, R, C>> Matrix<T, R, C, S> {
/// 4.0, 5.0, 6.0);
/// assert_eq!(m.row_sum_tr(), Vector3::new(5.0, 7.0, 9.0));
///
/// let mint = Matrix3x2::new(1,2,3,4,5,6);
/// assert_eq!(mint.row_sum_tr(), Vector2::new(9,12));
/// let mint = Matrix3x2::new(1, 2,
/// 3, 4,
/// 5, 6);
/// assert_eq!(mint.row_sum_tr(), Vector2::new(9, 12));
/// ```
#[inline]
#[must_use]
@ -173,8 +177,10 @@ impl<T: Scalar, R: Dim, C: Dim, S: RawStorage<T, R, C>> Matrix<T, R, C, S> {
/// 4.0, 5.0, 6.0);
/// assert_eq!(m.column_sum(), Vector2::new(6.0, 15.0));
///
/// let mint = Matrix3x2::new(1,2,3,4,5,6);
/// assert_eq!(mint.column_sum(), Vector3::new(3,7,11));
/// let mint = Matrix3x2::new(1, 2,
/// 3, 4,
/// 5, 6);
/// assert_eq!(mint.column_sum(), Vector3::new(3, 7, 11));
/// ```
#[inline]
#[must_use]
@ -189,6 +195,120 @@ impl<T: Scalar, R: Dim, C: Dim, S: RawStorage<T, R, C>> Matrix<T, R, C, S> {
})
}
/*
*
* Product computation.
*
*/
/// The product of all the elements of this matrix.
///
/// # Example
///
/// ```
/// # use nalgebra::Matrix2x3;
///
/// let m = Matrix2x3::new(1.0, 2.0, 3.0,
/// 4.0, 5.0, 6.0);
/// assert_eq!(m.product(), 720.0);
/// ```
#[inline]
#[must_use]
pub fn product(&self) -> T
where
T: ClosedMul + One,
{
self.iter().cloned().fold(T::one(), |a, b| a * b)
}
/// The product of all the rows of this matrix.
///
/// Use `.row_sum_tr` if you need the result in a column vector instead.
///
/// # Example
///
/// ```
/// # use nalgebra::{Matrix2x3, Matrix3x2};
/// # use nalgebra::{RowVector2, RowVector3};
///
/// let m = Matrix2x3::new(1.0, 2.0, 3.0,
/// 4.0, 5.0, 6.0);
/// assert_eq!(m.row_product(), RowVector3::new(4.0, 10.0, 18.0));
///
/// let mint = Matrix3x2::new(1, 2,
/// 3, 4,
/// 5, 6);
/// assert_eq!(mint.row_product(), RowVector2::new(15, 48));
/// ```
#[inline]
#[must_use]
pub fn row_product(&self) -> RowOVector<T, C>
where
T: ClosedMul + One,
DefaultAllocator: Allocator<T, U1, C>,
{
self.compress_rows(|col| col.product())
}
/// The product of all the rows of this matrix. The result is transposed and returned as a column vector.
///
/// # Example
///
/// ```
/// # use nalgebra::{Matrix2x3, Matrix3x2};
/// # use nalgebra::{Vector2, Vector3};
///
/// let m = Matrix2x3::new(1.0, 2.0, 3.0,
/// 4.0, 5.0, 6.0);
/// assert_eq!(m.row_product_tr(), Vector3::new(4.0, 10.0, 18.0));
///
/// let mint = Matrix3x2::new(1, 2,
/// 3, 4,
/// 5, 6);
/// assert_eq!(mint.row_product_tr(), Vector2::new(15, 48));
/// ```
#[inline]
#[must_use]
pub fn row_product_tr(&self) -> OVector<T, C>
where
T: ClosedMul + One,
DefaultAllocator: Allocator<T, C>,
{
self.compress_rows_tr(|col| col.product())
}
/// The product of all the columns of this matrix.
///
/// # Example
///
/// ```
/// # use nalgebra::{Matrix2x3, Matrix3x2};
/// # use nalgebra::{Vector2, Vector3};
///
/// let m = Matrix2x3::new(1.0, 2.0, 3.0,
/// 4.0, 5.0, 6.0);
/// assert_eq!(m.column_product(), Vector2::new(6.0, 120.0));
///
/// let mint = Matrix3x2::new(1, 2,
/// 3, 4,
/// 5, 6);
/// assert_eq!(mint.column_product(), Vector3::new(2, 12, 30));
/// ```
#[inline]
#[must_use]
pub fn column_product(&self) -> OVector<T, R>
where
T: ClosedMul + One,
DefaultAllocator: Allocator<T, R>,
{
let nrows = self.shape_generic().0;
self.compress_columns(
OVector::repeat_generic(nrows, Const::<1>, T::one()),
|out, col| {
out.component_mul_assign(&col);
},
)
}
/*
*
* Variance computation.