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 | 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 28x 28x 28x 28x 28x 28x 28x 28x 28x 28x 28x 28x 28x 28x 22x 28x 15x 15x 45x 45x 45x 45x 45x 90x 90x 90x 90x 45x 45x 45x 45x 15x 15x 13x 13x 28x 39x 39x 39x 39x 39x 78x 78x 78x 78x 39x 39x 39x 39x 13x 28x 3x 3x 3x 3x 3x | /**
* @license Apache-2.0
*
* Copyright (c) 2024 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 //
/**
* Performs the symmetric rank 1 operation `A = α*x*x^T + A` where `α` is a scalar, `x` is an `N` element vector, and `A` is an `N` by `N` symmetric matrix supplied in packed form.
*
* @private
* @param {string} order - storage layout
* @param {string} uplo - specifies whether the upper or lower triangular part of the symmetric matrix `A` is supplied
* @param {NonNegativeInteger} N - number of elements along each dimension of `A`
* @param {number} alpha - scalar
* @param {Float64Array} x - input vector
* @param {integer} strideX - `x` stride length
* @param {NonNegativeInteger} offsetX - starting index for `x`
* @param {Float64Array} AP - packed form of a symmetric matrix `A`
* @param {integer} strideAP - `AP` stride length
* @param {NonNegativeInteger} offsetAP - starting index for `AP`
* @returns {Float64Array} `A`
*
* @example
* var Float64Array = require( '@stdlib/array/float64' );
*
* var AP = new Float64Array( [ 1.0, 2.0, 3.0, 1.0, 2.0, 1.0 ] ); // => [ [ 1.0, 2.0, 3.0 ], [ 0.0, 1.0, 2.0 ], [ 0.0, 0.0, 1.0 ] ]
* var x = new Float64Array( [ 1.0, 2.0, 3.0 ] );
*
* dspr( 'row-major', 'upper', 3, 1.0, x, 1, 0, AP, 1, 0 );
* // AP => <Float64Array>[ 2.0, 4.0, 6.0, 5.0, 8.0, 10.0 ]
*/
function dspr( order, uplo, N, alpha, x, strideX, offsetX, AP, strideAP, offsetAP ) { // eslint-disable-line max-len
var tmp;
var ix0;
var ix1;
var iap;
var i0;
var i1;
var kk;
var ox;
ox = offsetX;
kk = offsetAP;
if (
( order === 'column-major' && uplo === 'upper' ) ||
( order === 'row-major' && uplo === 'lower' )
) {
ix1 = ox;
for ( i1 = 0; i1 < N; i1++ ) {
if ( x[ ix1 ] !== 0.0 ) {
tmp = alpha * x[ ix1 ];
ix0 = ox;
iap = kk;
for ( i0 = 0; i0 <= i1; i0++ ) {
AP[ iap ] += x[ ix0 ] * tmp;
ix0 += strideX;
iap += strideAP;
}
}
ix1 += strideX;
kk += ( i1 + 1 ) * strideAP;
}
return AP;
}
// ( order === 'column-major' && uplo === 'lower' ) || ( order === 'row-major' && uplo === 'upper' )
ix1 = ox;
for ( i1 = 0; i1 < N; i1++ ) {
if ( x[ ix1 ] !== 0.0 ) {
tmp = alpha * x[ ix1 ];
ix0 = ix1;
iap = kk;
for ( i0 = 0; i0 < N - i1; i0++ ) {
AP[ iap ] += x[ ix0 ] * tmp;
ix0 += strideX;
iap += strideAP;
}
}
ix1 += strideX;
kk += ( N - i1 ) * strideAP;
}
return AP;
}
// EXPORTS //
module.exports = dspr;
|