105 lines
2.2 KiB
JavaScript
105 lines
2.2 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 isNegativeZero = require( '@stdlib/math/base/assert/is-negative-zero' );
|
||
|
|
|
||
|
|
|
||
|
|
// MAIN //
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Computes the minimum value of a double-precision floating-point strided array according to a mask.
|
||
|
|
*
|
||
|
|
* @param {PositiveInteger} N - number of indexed elements
|
||
|
|
* @param {Float64Array} x - input array
|
||
|
|
* @param {integer} strideX - `x` stride length
|
||
|
|
* @param {Uint8Array} mask - mask array
|
||
|
|
* @param {integer} strideMask - `mask` stride length
|
||
|
|
* @returns {number} minimum value
|
||
|
|
*
|
||
|
|
* @example
|
||
|
|
* var Float64Array = require( '@stdlib/array/float64' );
|
||
|
|
* var Uint8Array = require( '@stdlib/array/uint8' );
|
||
|
|
*
|
||
|
|
* var x = new Float64Array( [ 1.0, -2.0, -4.0, 2.0 ] );
|
||
|
|
* var mask = new Uint8Array( [ 0, 0, 1, 0 ] );
|
||
|
|
*
|
||
|
|
* var v = dmskmin( x.length, x, 1, mask, 1 );
|
||
|
|
* // returns -2.0
|
||
|
|
*/
|
||
|
|
function dmskmin( N, x, strideX, mask, strideMask ) {
|
||
|
|
var min;
|
||
|
|
var ix;
|
||
|
|
var im;
|
||
|
|
var v;
|
||
|
|
var i;
|
||
|
|
|
||
|
|
if ( N <= 0 ) {
|
||
|
|
return NaN;
|
||
|
|
}
|
||
|
|
if ( strideX < 0 ) {
|
||
|
|
ix = (1-N) * strideX;
|
||
|
|
} else {
|
||
|
|
ix = 0;
|
||
|
|
}
|
||
|
|
if ( strideMask < 0 ) {
|
||
|
|
im = (1-N) * strideMask;
|
||
|
|
} else {
|
||
|
|
im = 0;
|
||
|
|
}
|
||
|
|
for ( i = 0; i < N; i++ ) {
|
||
|
|
if ( mask[ im ] === 0 ) {
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
ix += strideX;
|
||
|
|
im += strideMask;
|
||
|
|
}
|
||
|
|
if ( i === N ) {
|
||
|
|
return NaN;
|
||
|
|
}
|
||
|
|
min = x[ ix ];
|
||
|
|
if ( isnan( min ) ) {
|
||
|
|
return min;
|
||
|
|
}
|
||
|
|
i += 1;
|
||
|
|
for ( i; i < N; i++ ) {
|
||
|
|
ix += strideX;
|
||
|
|
im += strideMask;
|
||
|
|
if ( mask[ im ] ) {
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
v = x[ ix ];
|
||
|
|
if ( isnan( v ) ) {
|
||
|
|
return v;
|
||
|
|
}
|
||
|
|
if ( v < min || ( v === min && isNegativeZero( v ) ) ) {
|
||
|
|
min = v;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return min;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
// EXPORTS //
|
||
|
|
|
||
|
|
module.exports = dmskmin;
|