89 lines
1.8 KiB
JavaScript
89 lines
1.8 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 abs = require( '@stdlib/math/base/special/abs' );
|
|
|
|
|
|
// MAIN //
|
|
|
|
/**
|
|
* Computes the minimum absolute value of a strided array, ignoring `NaN` values.
|
|
*
|
|
* @param {PositiveInteger} N - number of indexed elements
|
|
* @param {NumericArray} x - input array
|
|
* @param {integer} stride - stride length
|
|
* @param {NonNegativeInteger} offset - starting index
|
|
* @returns {number} minimum absolute value
|
|
*
|
|
* @example
|
|
* var floor = require( '@stdlib/math/base/special/floor' );
|
|
*
|
|
* var x = [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0, NaN, NaN ];
|
|
* var N = floor( x.length / 2 );
|
|
*
|
|
* var v = nanminabs( N, x, 2, 1 );
|
|
* // returns 1.0
|
|
*/
|
|
function nanminabs( N, x, stride, offset ) {
|
|
var min;
|
|
var ix;
|
|
var v;
|
|
var i;
|
|
|
|
if ( N <= 0 ) {
|
|
return NaN;
|
|
}
|
|
if ( N === 1 || stride === 0 ) {
|
|
return x[ offset ];
|
|
}
|
|
ix = offset;
|
|
for ( i = 0; i < N; i++ ) {
|
|
v = x[ ix ];
|
|
if ( v === v ) {
|
|
break;
|
|
}
|
|
ix += stride;
|
|
}
|
|
if ( i === N ) {
|
|
return NaN;
|
|
}
|
|
min = abs( v );
|
|
i += 1;
|
|
for ( i; i < N; i++ ) {
|
|
ix += stride;
|
|
v = abs( x[ ix ] );
|
|
if ( isnan( v ) ) {
|
|
continue;
|
|
}
|
|
if ( v < min ) {
|
|
min = v;
|
|
}
|
|
}
|
|
return min;
|
|
}
|
|
|
|
|
|
// EXPORTS //
|
|
|
|
module.exports = nanminabs;
|