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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 | 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 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 | /**
* @license Apache-2.0
*
* Copyright (c) 2018 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 zeros = require( '@stdlib/array/base/zeros' );
var getSubscripts = require( './assign.js' );
// MAIN //
/**
* Converts a linear index to an array of subscripts.
*
* ## Notes
*
* - The function accepts the following "modes":
*
* - **throw**: throw an error when a linear index exceeds array dimensions.
* - **normalize**: normalize negative indices and throw an error when a linear index exceeds array dimensions.
* - **wrap**: wrap around a linear index exceeding array dimensions using modulo arithmetic.
* - **clamp**: set a linear index exceeding array dimensions to either `0` (minimum linear index) or the maximum linear index.
*
* - When provided a stride array containing negative strides, if an `offset` is greater than `0`, the function interprets the linear index as an index into the underlying data buffer for the array, thus returning subscripts from the perspective of that buffer. If an `offset` is equal to `0`, the function treats the linear index as an index into an array view, thus returning subscripts from the perspective of that view.
*
* ```text
* Dims: 2x2
* Buffer: [ 1, 2, 3, 4 ]
*
* View = [ a00, a01,
* a10, a11 ]
*
* Strides: 2,1
* Offset: 0
*
* View = [ 1, 2,
* 3, 4 ]
*
* Strides: 2,-1
* Offset: 1
*
* View = [ 2, 1,
* 4, 3 ]
*
* Strides: -2,1
* Offset: 2
*
* View = [ 3, 4,
* 1, 2 ]
*
* Strides: -2,-1
* Offset: 3
*
* View = [ 4, 3,
* 2, 1 ]
* ```
*
* ```javascript
* var shape = [ 2, 2 ];
* var order = 'row-major';
* var strides = [ -2, 1 ];
* var offset = 2;
* var mode = 'throw';
*
* // From the perspective of a view...
* var s = ind2sub( shape, strides, 0, order, 0, mode );
* // returns [ 0, 0 ]
*
* s = ind2sub( shape, strides, 0, order, 1, mode );
* // returns [ 0, 1 ]
*
* s = ind2sub( shape, strides, 0, order, 2, mode );
* // returns [ 1, 0 ]
*
* s = ind2sub( shape, strides, 0, order, 3, mode );
* // returns [ 1, 1 ]
*
* // From the perspective of an underlying buffer...
* s = ind2sub( shape, strides, offset, order, 0, mode );
* // returns [ 1, 0 ]
*
* s = ind2sub( shape, strides, offset, order, 1, mode );
* // returns [ 1, 1 ]
*
* s = ind2sub( shape, strides, offset, order, 2, mode );
* // returns [ 0, 0 ]
*
* s = ind2sub( shape, strides, offset, order, 3, mode );
* // returns [ 0, 1 ]
* ```
*
* In short, from the perspective of a view, view data is always ordered.
*
* @param {NonNegativeIntegerArray} shape - array shape
* @param {IntegerArray} strides - stride array
* @param {NonNegativeInteger} offset - location of the first indexed value **based** on the stride array
* @param {string} order - specifies whether an array is row-major (C-style) or column-major (Fortran-style)
* @param {integer} idx - linear index
* @param {string} mode - specifies how to handle a linear index which exceeds array dimensions
* @throws {RangeError} linear index must not exceed array dimensions
* @returns {Array} subscripts
*
* @example
* var shape = [ 3, 3, 3 ];
* var strides = [ 9, 6, 1 ];
* var offset = 0;
* var order = 'row-major';
*
* var s = ind2sub( shape, strides, offset, order, 17, 'throw' );
* // returns [ 1, 2, 2 ]
*/
function ind2sub( shape, strides, offset, order, idx, mode ) {
return getSubscripts( shape, strides, offset, order, idx, mode, zeros( shape.length ) ); // eslint-disable-line max-len
}
// EXPORTS //
module.exports = ind2sub;
|