82 lines
1.9 KiB
JavaScript
82 lines
1.9 KiB
JavaScript
/**
|
|
* @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';
|
|
|
|
// MAIN //
|
|
|
|
/**
|
|
* Computes the maximum linear index in an underlying data buffer accessible to an array view.
|
|
*
|
|
* @param {NonNegativeIntegerArray} shape - array shape
|
|
* @param {IntegerArray} strides - stride array
|
|
* @param {NonNegativeInteger} offset - index offset
|
|
* @returns {NonNegativeInteger} linear index
|
|
*
|
|
* @example
|
|
* var shape = [ 10, 10 ];
|
|
* var strides = [ 10, 1 ];
|
|
* var offset = 0;
|
|
*
|
|
* var idx = maxViewBufferIndex( shape, strides, offset );
|
|
* // returns 99
|
|
*
|
|
* @example
|
|
* var shape = [ 10, 10 ];
|
|
* var strides = [ -10, -1 ];
|
|
* var offset = 99;
|
|
*
|
|
* var idx = maxViewBufferIndex( shape, strides, offset );
|
|
* // returns 99
|
|
*
|
|
* @example
|
|
* var shape = [ 10, 10 ];
|
|
* var strides = [ 1, 10 ];
|
|
* var offset = 0;
|
|
*
|
|
* var idx = maxViewBufferIndex( shape, strides, offset );
|
|
* // returns 99
|
|
*
|
|
* @example
|
|
* var shape = [ 10, 10 ];
|
|
* var strides = [ -1, -10 ];
|
|
* var offset = 99;
|
|
*
|
|
* var idx = maxViewBufferIndex( shape, strides, offset );
|
|
* // returns 99
|
|
*/
|
|
function maxViewBufferIndex( shape, strides, offset ) {
|
|
var ndims;
|
|
var idx;
|
|
var i;
|
|
|
|
ndims = shape.length;
|
|
idx = offset;
|
|
for ( i = 0; i < ndims; i++ ) {
|
|
if ( strides[ i ] > 0 ) {
|
|
idx += strides[ i ] * (shape[ i ] - 1);
|
|
}
|
|
}
|
|
return idx;
|
|
}
|
|
|
|
|
|
// EXPORTS //
|
|
|
|
module.exports = maxViewBufferIndex;
|