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

Add select_rows and select_columns.

Browse Source
This commit is contained in:
sebcrozet 2018-12-09 12:22:10 +01:00
parent 01d1f9d24b
commit bba1f48e81
2 changed files with 46 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
src/base/construction.rs
View File

@ -296,7 +296,7 @@ where
///
/// let m = Matrix3::from_diagonal(&Vector3::new(1.0, 2.0, 3.0));
/// // The two additional arguments represent the matrix dimensions.
/// let dm = DMatrix::from_diagonal(&DVector::from_row_slice(3, &[1.0, 2.0, 3.0]));
/// let dm = DMatrix::from_diagonal(&DVector::from_row_slice(&[1.0, 2.0, 3.0]));
///
/// assert!(m.m11 == 1.0 && m.m12 == 0.0 && m.m13 == 0.0 &&
/// m.m21 == 0.0 && m.m22 == 2.0 && m.m23 == 0.0 &&
@ -616,7 +616,7 @@ macro_rules! impl_constructors_from_data(
///
/// let v = Vector3::from_row_slice(&[0, 1, 2]);
/// // The additional argument represents the vector dimension.
/// let dv = DVector::from_row_slice(3, &[0, 1, 2]);
/// let dv = DVector::from_row_slice(&[0, 1, 2]);
/// let m = Matrix2x3::from_row_slice(&[0, 1, 2, 3, 4, 5]);
/// // The two additional arguments represent the matrix dimensions.
/// let dm = DMatrix::from_row_slice(2, 3, &[0, 1, 2, 3, 4, 5]);
@ -643,7 +643,7 @@ macro_rules! impl_constructors_from_data(
///
/// let v = Vector3::from_column_slice(&[0, 1, 2]);
/// // The additional argument represents the vector dimension.
/// let dv = DVector::from_column_slice(3, &[0, 1, 2]);
/// let dv = DVector::from_column_slice(&[0, 1, 2]);
/// let m = Matrix2x3::from_column_slice(&[0, 1, 2, 3, 4, 5]);
/// // The two additional arguments represent the matrix dimensions.
/// let dm = DMatrix::from_column_slice(2, 3, &[0, 1, 2, 3, 4, 5]);

45
src/base/edition.rs
View File

@ -1,6 +1,7 @@
use num::{One, Zero};
use std::cmp;
use std::ptr;
use std::iter::ExactSizeIterator;
use base::allocator::{Allocator, Reallocator};
use base::constraint::{DimEq, SameNumberOfColumns, SameNumberOfRows, ShapeConstraint};
@ -32,6 +33,46 @@ impl<N: Scalar + Zero, R: Dim, C: Dim, S: Storage<N, R, C>> Matrix<N, R, C, S> {
res
}
/// Creates a new matrix by extracting the given set of rows from `self`.
pub fn select_rows(&self, irows: impl ExactSizeIterator<Item = usize> + Clone) -> MatrixMN<N, Dynamic, C>
where DefaultAllocator: Allocator<N, Dynamic, C> {
let ncols = self.data.shape().1;
let mut res = unsafe { MatrixMN::new_uninitialized_generic(Dynamic::new(irows.len()), ncols) };
// First, check that all the indices from irows are valid.
// This will allow us to use unchecked access in the inner loop.
for i in irows.clone() {
assert!(i < self.nrows(), "Row index out of bounds.")
}
for j in 0..ncols.value() {
// FIXME: use unchecked column indexing
let mut res = res.column_mut(j);
let mut src = self.column(j);
for (destination, source) in irows.clone().enumerate() {
unsafe {
*res.vget_unchecked_mut(destination) = *src.vget_unchecked(source)
}
}
}
res
}
/// Creates a new matrix by extracting the given set of columns from `self`.
pub fn select_columns(&self, icols: impl ExactSizeIterator<Item = usize>) -> MatrixMN<N, R, Dynamic>
where DefaultAllocator: Allocator<N, R, Dynamic> {
let nrows = self.data.shape().0;
let mut res = unsafe { MatrixMN::new_uninitialized_generic(nrows, Dynamic::new(icols.len())) };
for (destination, source) in icols.enumerate() {
res.column_mut(destination).copy_from(&self.column(source))
}
res
}
}
impl<N: Scalar, R: Dim, C: Dim, S: StorageMut<N, R, C>> Matrix<N, R, C, S> {
@ -764,9 +805,9 @@ where
/// # Example
/// ```
/// # use nalgebra::DVector;
/// let mut vector = DVector::from_vec(3, vec![0, 1, 2]);
/// let mut vector = DVector::from_vec(vec![0, 1, 2]);
/// vector.extend(vec![3, 4, 5]);
/// assert!(vector.eq(&DVector::from_vec(6, vec![0, 1, 2, 3, 4, 5])));
/// assert!(vector.eq(&DVector::from_vec(vec![0, 1, 2, 3, 4, 5])));
/// ```
fn extend<I: IntoIterator<Item=N>>(&mut self, iter: I) {
self.data.extend(iter);