Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 | 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 72x 72x 72x 72x 72x 72x 72x 72x 72x 72x 20x 20x 52x 52x 52x 52x 72x 46x 46x 29x 29x 46x 23x 72x 1x 1x 22x 72x 5x 72x 17x 17x 22x 22x 72x 48x 48x 72x 28x 28x 22x 72x 1x 1x 1x 1x 1x | /**
* @license Apache-2.0
*
* Copyright (c) 2026 The Stdlib Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
'use strict';
// MODULES //
var isndarrayLike = require( '@stdlib/assert/is-ndarray-like' );
var args2multislice = require( '@stdlib/slice/base/args2multislice' );
var base = require( '@stdlib/ndarray/base/slice' );
var getShape = require( '@stdlib/ndarray/shape' );
var zeroTo = require( '@stdlib/array/base/zero-to' );
var objectAssign = require( '@stdlib/object/assign' );
var format = require( '@stdlib/string/format' );
var defaults = require( './defaults.json' );
var validate = require( './validate.js' );
// MAIN //
/**
* Returns a read-only view of the last element (or subarray) along one or more ndarray dimensions.
*
* ## Notes
*
* - By default, the function performs the operation over all dimensions and thus returns the last element of the input ndarray as a zero-dimensional ndarray.
* - If provided an empty `dims` array, the function returns a read-only view of the input ndarray.
* - If provided a zero-dimensional input ndarray, the function returns a read-only view of the input ndarray.
*
* @param {ndarray} x - input ndarray
* @param {Options} [options] - function options
* @param {IntegerArray} [options.dims] - list of dimensions over which to perform the operation
* @throws {TypeError} first argument must be an ndarray-like object
* @throws {TypeError} options argument must be an object
* @throws {TypeError} `dims` option must be an array of integers
* @throws {RangeError} `dims` option contains an out-of-bounds dimension index
* @throws {Error} `dims` option contains duplicate indices
* @returns {ndarray} ndarray view
*
* @example
* var array = require( '@stdlib/ndarray/array' );
*
* var x = array( [ [ 1.0, 2.0 ], [ 3.0, 4.0 ] ] );
* // returns <ndarray>[ [ 1.0, 2.0 ], [ 3.0, 4.0 ] ]
*
* var v = last( x );
* // returns <ndarray>[ 4.0 ]
*
* v = last( x, {
* 'dims': [ -1 ]
* });
* // returns <ndarray>[ 2.0, 4.0 ]
*
* v = last( x, {
* 'dims': [ -2 ]
* });
* // returns <ndarray>[ 3.0, 4.0 ]
*/
function last( x, options ) {
var args;
var opts;
var dims;
var err;
var sh;
var N;
var i;
if ( !isndarrayLike( x ) ) {
throw new TypeError( format( 'invalid argument. First argument must be an ndarray-like object. Value: `%s`.', x ) );
}
sh = getShape( x );
N = sh.length;
opts = objectAssign( {}, defaults );
if ( arguments.length > 1 ) {
err = validate( opts, N, options );
if ( err ) {
throw err;
}
}
// Handle the 0-D case by returning a view of the input ndarray:
if ( N === 0 ) {
return base( x, args2multislice( [] ), true, false );
}
// When a list of dimensions is not provided, perform the operation across all dimensions...
if ( opts.dims === null ) {
dims = zeroTo( N );
} else {
dims = opts.dims;
}
// Build a list of slice arguments such that each dimension in `dims` resolves to its last index and all other dimensions are kept in full:
args = [];
for ( i = 0; i < N; i++ ) {
args.push( null );
}
for ( i = 0; i < dims.length; i++ ) {
args[ dims[ i ] ] = sh[ dims[ i ] ] - 1;
}
return base( x, args2multislice( args ), true, false );
}
// EXPORTS //
module.exports = last;
|