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 | 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 32x 32x 32x 2x 2x 2x 2x 2x | /**
* @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 base = require( './base.js' );
// MAIN //
/**
* Computes an approximation to the smallest eigenvalue using values of d from the previous transform.
*
* ## Notes
*
* - `Z` is a 1-D array of length >= `4*N0` storing interleaved q/e values.
* - `PP` is `0` for ping, `1` for pong.
* - `TAU` is approximation to the smallest eigenvalue and is used as a shift to accelerate convergence of the dqds iteration.
* - `TTYPE` is an integer flag describing how TAU was computed.
* - `G` is a state variable that is preserved across successive calls and is used to regulate the magnitude of fallback shifts.
*
* @param {integer} I0 - first index
* @param {integer} N0 - last index
* @param {Float64Array} Z - qd array
* @param {integer} PP - ping-pong flag (0 or 1)
* @param {integer} N0IN - value of `N0` at the start of `EIGTEST`
* @param {number} DMIN - minimum value of `d`
* @param {number} DMIN1 - minimum value of `d`, excluding `D(N0)`
* @param {number} DMIN2 - minimum value of `d`, excluding `D(N0)` and `D(N0-1)`
* @param {number} DN - `d(N)`
* @param {number} DN1 - `d(N-1)`
* @param {number} DN2 - `d(N-2)`
* @param {number} G - saved state carried across calls
* @param {Float64Array} out - output array containing `tau`, `ttype`, and `G`
* @returns {Float64Array} output array
*
* @example
* var Float64Array = require( '@stdlib/array/float64' );
*
* var out = new Float64Array( 3 );
* var Z = new Float64Array( [ 5, 0, 7, 0, 9, 0, 3, 0, 10, 0, 4.5, 0, 18, 0, 0, 0 ] );
*
* dlasq4( 0, 3, Z, 0, 3, 0.2, 0.15, 0.1, 0.8, 0.7, 0.6, -6, out );
* // out => <Float64Array>[ ~0.05, -6, 0.25 ]
*/
function dlasq4( I0, N0, Z, PP, N0IN, DMIN, DMIN1, DMIN2, DN, DN1, DN2, G, out ) { // eslint-disable-line max-len, max-params
return base( I0, N0, Z, 1, 0, PP, N0IN, DMIN, DMIN1, DMIN2, DN, DN1, DN2, G, out, 1, 0 );
}
// EXPORTS //
module.exports = dlasq4;
|