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 | 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) 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';
// MODULES //
var isRowMajor = require( '@stdlib/ndarray/base/assert/is-row-major-string' );
var isColumnMajor = require( '@stdlib/ndarray/base/assert/is-column-major-string' );
var f32 = require( '@stdlib/number/float64/base/to-float32' );
// 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 {Float32Array} x - input vector
* @param {integer} strideX - `x` stride length
* @param {NonNegativeInteger} offsetX - starting index for `x`
* @param {Float32Array} AP - packed form of a symmetric matrix `A`
* @param {integer} strideAP - `AP` stride length
* @param {NonNegativeInteger} offsetAP - starting index for `AP`
* @returns {Float32Array} `A`
*
* @example
* var Float32Array = require( '@stdlib/array/float32' );
*
* var AP = new Float32Array( [ 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 Float32Array( [ 1.0, 2.0, 3.0 ] );
*
* sspr( 'row-major', 'upper', 3, 1.0, x, 1, 0, AP, 1, 0 );
* // AP => <Float32Array>[ 2.0, 4.0, 6.0, 5.0, 8.0, 10.0 ]
*/
function sspr( 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 (
( isColumnMajor( order ) && uplo === 'upper' ) ||
( isRowMajor( order ) && uplo === 'lower' )
) {
ix1 = ox;
for ( i1 = 0; i1 < N; i1++ ) {
if ( x[ ix1 ] !== 0.0 ) {
tmp = f32( alpha * x[ ix1 ] );
ix0 = ox;
iap = kk;
for ( i0 = 0; i0 <= i1; i0++ ) {
AP[ iap ] += f32( 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 = f32( alpha * x[ ix1 ] );
ix0 = ix1;
iap = kk;
for ( i0 = 0; i0 < N - i1; i0++ ) {
AP[ iap ] += f32( x[ ix0 ] * tmp );
ix0 += strideX;
iap += strideAP;
}
}
ix1 += strideX;
kk += ( N - i1 ) * strideAP;
}
return AP;
}
// EXPORTS //
module.exports = sspr;
|