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 | 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) 2026 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 reinterpret = require( '@stdlib/strided/base/reinterpret-complex128' );
var real = require( '@stdlib/complex/float64/real' );
var imag = require( '@stdlib/complex/float64/imag' );
var zcopy = require( '@stdlib/blas/base/zcopy' ).ndarray;
var cmul = require( '@stdlib/complex/float64/base/mul' ).assign;
// VARIABLES //
var M = 5;
// MAIN //
/**
* Multiplies each element in a double-precision complex floating-point strided array `x` by a scalar constant and assigns the results to elements in a double-precision complex floating-point strided array `w` using alternative indexing semantics.
*
* @param {PositiveInteger} N - number of indexed elements
* @param {Complex128} alpha - scalar constant
* @param {Complex128Array} x - input array
* @param {integer} strideX - `x` stride length
* @param {NonNegativeInteger} offsetX - starting `x` index
* @param {Complex128Array} w - output array
* @param {integer} strideW - `w` stride length
* @param {NonNegativeInteger} offsetW - starting `w` index
* @returns {Complex128Array} output array
*
* @example
* var Complex128Array = require( '@stdlib/array/complex128' );
* var Complex128 = require( '@stdlib/complex/float64/ctor' );
*
* var x = new Complex128Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] );
* var w = new Complex128Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );
* var alpha = new Complex128( 5.0, 3.0 );
*
* zwax( x.length, alpha, x, 1, 0, w, 1, 0 );
* // w => <Complex128Array>[ -1.0, 13.0, 3.0, 29.0, 7.0, 45.0 ]
*/
function zwax( N, alpha, x, strideX, offsetX, w, strideW, offsetW ) {
var xview;
var wview;
var are;
var aim;
var ix;
var iw;
var sx;
var sw;
var m;
var i;
if ( N <= 0 ) {
return w;
}
// Decompose the constant into its real and imaginary components:
are = real( alpha );
aim = imag( alpha );
// Fast path: when alpha = 1+0i, delegate to zcopy (w = x)
if ( are === 1.0 && aim === 0.0 ) {
return zcopy( N, x, strideX, offsetX, w, strideW, offsetW );
}
// Reinterpret the complex input arrays as real-valued arrays:
xview = reinterpret( x, 0 );
wview = reinterpret( w, 0 );
// Adjust the strides and offsets according to the real-valued arrays:
ix = offsetX * 2;
iw = offsetW * 2;
sx = strideX * 2;
sw = strideW * 2;
// Use loop unrolling if both strides are equal to `1`...
if ( strideX === 1 && strideW === 1 ) {
m = N % M;
// If we have a remainder, run a clean-up loop...
if ( m > 0 ) {
for ( i = 0; i < m; i++ ) {
cmul( are, aim, xview[ ix ], xview[ ix+1 ], wview, 1, iw );
ix += sx;
iw += sw;
}
}
if ( N < M ) {
return w;
}
for ( i = m; i < N; i += M ) {
cmul( are, aim, xview[ ix ], xview[ ix+1 ], wview, 1, iw );
cmul( are, aim, xview[ ix+2 ], xview[ ix+3 ], wview, 1, iw+2 );
cmul( are, aim, xview[ ix+4 ], xview[ ix+5 ], wview, 1, iw+4 );
cmul( are, aim, xview[ ix+6 ], xview[ ix+7 ], wview, 1, iw+6 );
cmul( are, aim, xview[ ix+8 ], xview[ ix+9 ], wview, 1, iw+8 );
ix += M * 2;
iw += M * 2;
}
return w;
}
for ( i = 0; i < N; i++ ) {
cmul( are, aim, xview[ ix ], xview[ ix+1 ], wview, 1, iw );
ix += sx;
iw += sw;
}
return w;
}
// EXPORTS //
module.exports = zwax;
|