time-to-botec/js/node_modules/@stdlib/stats/base/max-by/lib/ndarray.js
NunoSempere b6addc7f05 feat: add the node modules
Necessary in order to clearly see the squiggle hotwiring.
2022-12-03 12:44:49 +00:00

98 lines
2.1 KiB
JavaScript

/**
* @license Apache-2.0
*
* Copyright (c) 2020 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 isnan = require( '@stdlib/math/base/assert/is-nan' );
var isPositiveZero = require( '@stdlib/math/base/assert/is-positive-zero' );
// MAIN //
/**
* Calculates the maximum value of a strided array via a callback function.
*
* @param {PositiveInteger} N - number of indexed elements
* @param {Collection} x - input array/collection
* @param {integer} stride - index increment
* @param {NonNegativeInteger} offset - starting index
* @param {Callback} clbk - callback
* @param {*} [thisArg] - execution context
* @returns {number} maximum value
*
* @example
* var x = [ -2.0, 1.0, 3.0, -5.0, 4.0, 0.0, -1.0, -3.0 ];
*
* function accessor( v ) {
* return v * 2.0;
* }
*
* var v = maxBy( x.length, x, 1, 0, accessor );
* // returns 8.0
*/
function maxBy( N, x, stride, offset, clbk, thisArg ) {
var max;
var ix;
var v;
var i;
if ( N <= 0 ) {
return NaN;
}
if ( N === 1 || stride === 0 ) {
v = clbk.call( thisArg, x[ 0 ], 0, 0, x );
if ( v === void 0 ) {
return NaN;
}
return v;
}
ix = offset;
for ( i = 0; i < N; i++ ) {
max = clbk.call( thisArg, x[ ix ], i, ix, x );
if ( max !== void 0 ) {
break;
}
ix += stride;
}
if ( i === N ) {
return NaN;
}
i += 1;
for ( i; i < N; i++ ) {
ix += stride;
v = clbk.call( thisArg, x[ ix ], i, ix, x );
if ( v === void 0 ) {
continue;
}
if ( isnan( v ) ) {
return v;
}
if ( v > max || ( v === max && isPositiveZero( v ) ) ) {
max = v;
}
}
return max;
}
// EXPORTS //
module.exports = maxBy;