ndarray/
impl_2d.rs

1// Copyright 2014-2016 bluss and ndarray developers.
2//
3// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
4// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
5// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
6// option. This file may not be copied, modified, or distributed
7// except according to those terms.
8
9//! Methods for two-dimensional arrays.
10use crate::imp_prelude::*;
11
12/// # Methods For 2-D Arrays
13impl<A, S> ArrayBase<S, Ix2>
14where
15    S: RawData<Elem = A>,
16{
17    /// Return an array view of row `index`.
18    ///
19    /// **Panics** if `index` is out of bounds.
20    ///
21    /// ```
22    /// use ndarray::array;
23    /// let array = array![[1., 2.], [3., 4.]];
24    /// assert_eq!(array.row(0), array![1., 2.]);
25    /// ```
26    pub fn row(&self, index: Ix) -> ArrayView1<'_, A>
27    where
28        S: Data,
29    {
30        self.index_axis(Axis(0), index)
31    }
32
33    /// Return a mutable array view of row `index`.
34    ///
35    /// **Panics** if `index` is out of bounds.
36    ///
37    /// ```
38    /// use ndarray::array;
39    /// let mut array = array![[1., 2.], [3., 4.]];
40    /// array.row_mut(0)[1] = 5.;
41    /// assert_eq!(array, array![[1., 5.], [3., 4.]]);
42    /// ```
43    pub fn row_mut(&mut self, index: Ix) -> ArrayViewMut1<'_, A>
44    where
45        S: DataMut,
46    {
47        self.index_axis_mut(Axis(0), index)
48    }
49
50    /// Return the number of rows (length of `Axis(0)`) in the two-dimensional array.
51    ///
52    /// ```
53    /// use ndarray::{array, Axis};
54    ///
55    /// let array = array![[1., 2.],
56    ///                    [3., 4.],
57    ///                    [5., 6.]];
58    /// assert_eq!(array.nrows(), 3);
59    ///
60    /// // equivalent ways of getting the dimensions
61    /// // get nrows, ncols by using dim:
62    /// let (m, n) = array.dim();
63    /// assert_eq!(m, array.nrows());
64    /// // get length of any particular axis with .len_of()
65    /// assert_eq!(m, array.len_of(Axis(0)));
66    /// ```
67    pub fn nrows(&self) -> usize {
68        self.len_of(Axis(0))
69    }
70
71    /// Return an array view of column `index`.
72    ///
73    /// **Panics** if `index` is out of bounds.
74    ///
75    /// ```
76    /// use ndarray::array;
77    /// let array = array![[1., 2.], [3., 4.]];
78    /// assert_eq!(array.column(0), array![1., 3.]);
79    /// ```
80    pub fn column(&self, index: Ix) -> ArrayView1<'_, A>
81    where
82        S: Data,
83    {
84        self.index_axis(Axis(1), index)
85    }
86
87    /// Return a mutable array view of column `index`.
88    ///
89    /// **Panics** if `index` is out of bounds.
90    ///
91    /// ```
92    /// use ndarray::array;
93    /// let mut array = array![[1., 2.], [3., 4.]];
94    /// array.column_mut(0)[1] = 5.;
95    /// assert_eq!(array, array![[1., 2.], [5., 4.]]);
96    /// ```
97    pub fn column_mut(&mut self, index: Ix) -> ArrayViewMut1<'_, A>
98    where
99        S: DataMut,
100    {
101        self.index_axis_mut(Axis(1), index)
102    }
103
104    /// Return the number of columns (length of `Axis(1)`) in the two-dimensional array.
105    ///
106    /// ```
107    /// use ndarray::{array, Axis};
108    ///
109    /// let array = array![[1., 2.],
110    ///                    [3., 4.],
111    ///                    [5., 6.]];
112    /// assert_eq!(array.ncols(), 2);
113    ///
114    /// // equivalent ways of getting the dimensions
115    /// // get nrows, ncols by using dim:
116    /// let (m, n) = array.dim();
117    /// assert_eq!(n, array.ncols());
118    /// // get length of any particular axis with .len_of()
119    /// assert_eq!(n, array.len_of(Axis(1)));
120    /// ```
121    pub fn ncols(&self) -> usize {
122        self.len_of(Axis(1))
123    }
124
125    /// Return true if the array is square, false otherwise.
126    ///
127    /// # Examples
128    /// Square:
129    /// ```
130    /// use ndarray::array;
131    /// let array = array![[1., 2.], [3., 4.]];
132    /// assert!(array.is_square());
133    /// ```
134    /// Not square:
135    /// ```
136    /// use ndarray::array;
137    /// let array = array![[1., 2., 5.], [3., 4., 6.]];
138    /// assert!(!array.is_square());
139    /// ```
140    pub fn is_square(&self) -> bool {
141        let (m, n) = self.dim();
142        m == n
143    }
144}
ndarray/impl_2d.rs

ndarray/
impl_2d.rs
