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feat: add cfftfi, cffti, decompose, update cfftf
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‎lib/node_modules/@stdlib/fft/base/fftpack/lib/cfftf.js‎

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@@ -77,6 +77,8 @@ var cfftf1 = require( './cfftf1.js' );
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function cfftf( n, c, wsave ) {
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var iw1;
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var iw2;
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// Function Body:
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if ( n === 1 ) {
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return;
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}

‎lib/node_modules/@stdlib/fft/base/fftpack/lib/cffti.js‎

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/**
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* @license Apache-2.0
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*
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* Copyright (c) 2025 The Stdlib Authors.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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*
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* ## Notice
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*
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* The original C code and copyright notice are from the [PFFFT library]{@link https://github.com/marton78/pffft/blob/master/fftpack.c}. The implementation follows the original, but has been modified for JavaScript.
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*
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* ```text
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* Copyright (c) 2004 the University Corporation for Atmospheric
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* Research ("UCAR"). All rights reserved. Developed by NCAR's
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* Computational and Information Systems Laboratory, UCAR,
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* www.cisl.ucar.edu.
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*
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* Redistribution and use of the Software in source and binary forms,
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* with or without modification, is permitted provided that the
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* following conditions are met:
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*
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* - Neither the names of NCAR's Computational and Information Systems
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* Laboratory, the University Corporation for Atmospheric Research,
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* nor the names of its sponsors or contributors may be used to
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* endorse or promote products derived from this Software without
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* specific prior written permission.
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*
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* - Redistributions of source code must retain the above copyright
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* notices, this list of conditions, and the disclaimer below.
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*
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* - Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions, and the disclaimer below in the
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* documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE CONTRIBUTORS OR COPYRIGHT
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* HOLDERS BE LIABLE FOR ANY CLAIM, INDIRECT, INCIDENTAL, SPECIAL,
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS WITH THE
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* SOFTWARE.
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* ```
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*/
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'use strict';
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// MODULES //
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var cffti1 = require( './cffti1.js' );
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// MAIN //
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/**
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* Initializes the working array for the complex FFT.
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*
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* @private
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* @param {number} n - length of the sequence to transform
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* @param {Float64Array} wsave - working array containing precomputed values
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* @returns {void}
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*/
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function cffti( n, wsave ) {
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var iw1;
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var iw2;
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// Function Body:
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if ( n === 1 ) {
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return;
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}
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iw1 = ( 2 * n ) + 1;
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iw2 = iw1 + ( 2 * n );
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cffti1( n, wsave[ iw1 - 1 ], wsave[ iw2 - 1 ] );
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}
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// EXPORTS //
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module.exports = cffti;

‎lib/node_modules/@stdlib/fft/base/fftpack/lib/cffti1.js‎

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/**
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* @license Apache-2.0
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*
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* Copyright (c) 2025 The Stdlib Authors.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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*
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* ## Notice
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*
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* The original C code and copyright notice are from the [PFFFT library]{@link https://github.com/marton78/pffft/blob/master/fftpack.c}. The implementation follows the original, but has been modified for JavaScript.
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*
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* ```text
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* Copyright (c) 2004 the University Corporation for Atmospheric
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* Research ("UCAR"). All rights reserved. Developed by NCAR's
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* Computational and Information Systems Laboratory, UCAR,
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* www.cisl.ucar.edu.
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*
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* Redistribution and use of the Software in source and binary forms,
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* with or without modification, is permitted provided that the
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* following conditions are met:
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*
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* - Neither the names of NCAR's Computational and Information Systems
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* Laboratory, the University Corporation for Atmospheric Research,
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* nor the names of its sponsors or contributors may be used to
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* endorse or promote products derived from this Software without
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* specific prior written permission.
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*
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* - Redistributions of source code must retain the above copyright
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* notices, this list of conditions, and the disclaimer below.
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*
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* - Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions, and the disclaimer below in the
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* documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO THE WARRANTIES OF
49+
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE CONTRIBUTORS OR COPYRIGHT
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* HOLDERS BE LIABLE FOR ANY CLAIM, INDIRECT, INCIDENTAL, SPECIAL,
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS WITH THE
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* SOFTWARE.
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* ```
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*/
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'use strict';
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// MODULES //
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var sin = require( '@stdlib/math/base/special/sin' );
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var cos = require( '@stdlib/math/base/special/cos' );
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var TWO_PI = require( '@stdlib/constants/float64/two-pi' );
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var decompose = require( './decompose.js' );
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// VARIABLES //
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var NTRYH = [ 3, 4, 2, 5 ]; // Initial trial factors for FFT factorization
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// MAIN //
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/**
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* Initializes the working arrays for the FFT algorithm.
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*
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* @private
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* @param {number} n - length of the sequence
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* @param {Float64Array} wa - array of twiddle factors
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* @param {Int32Array} ifac - array containing factorization information
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* @returns {void}
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*/
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function cffti1( n, wa, ifac ) {
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var argld;
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var argh;
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var idot;
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var ipm;
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var ido;
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var arg;
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var nf;
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var ip;
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var ii;
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var ld;
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var fi;
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var l2;
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var l1;
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var k1;
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var i1;
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var j;
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var i;
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nf = decompose( n, ifac, NTRYH );
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argh = TWO_PI / n;
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i = 2;
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l1 = 1;
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for ( k1 = 1; k1 <= nf; k1++ ) {
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ip = ifac[ k1 + 2 - 1 ];
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ld = 0;
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l2 = ip * l1;
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ido = n / l2;
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idot = ido + ido + 2;
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ipm = ip - 1;
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for ( j = 1; j <= ipm; j++ ) {
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i1 = i;
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wa[ i - 1 - 1 ] = 1.0;
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wa[ i - 1 ] = 0.0;
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ld += l1;
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fi = 0.0;
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argld = ld * argh;
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for ( ii = 4; ii <= idot; ii += 2 ) {
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i += 2;
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fi += 1.0;
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arg = fi * argld;
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wa[ i - 1 - 1 ] = cos( arg );
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wa[ i - 1 ] = sin( arg );
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}
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if ( ip > 5 ) {
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wa[ i1 - 1 - 1 ] = wa[ i - 1 - 1 ];
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wa[ i1 - 1 ] = wa[ i - 1 ];
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}
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}
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l1 = l2;
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}
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}
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// EXPORTS //
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module.exports = cffti1;

‎lib/node_modules/@stdlib/fft/base/fftpack/lib/decompose.js‎

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/**
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* @license Apache-2.0
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*
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* Copyright (c) 2025 The Stdlib Authors.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
14+
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15+
* See the License for the specific language governing permissions and
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* limitations under the License.
17+
*
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*
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* ## Notice
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*
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* The original C code and copyright notice are from the [PFFFT library]{@link https://github.com/marton78/pffft/blob/master/fftpack.c}. The implementation follows the original, but has been modified for JavaScript.
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*
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* ```text
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* Copyright (c) 2004 the University Corporation for Atmospheric
25+
* Research ("UCAR"). All rights reserved. Developed by NCAR's
26+
* Computational and Information Systems Laboratory, UCAR,
27+
* www.cisl.ucar.edu.
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*
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* Redistribution and use of the Software in source and binary forms,
30+
* with or without modification, is permitted provided that the
31+
* following conditions are met:
32+
*
33+
* - Neither the names of NCAR's Computational and Information Systems
34+
* Laboratory, the University Corporation for Atmospheric Research,
35+
* nor the names of its sponsors or contributors may be used to
36+
* endorse or promote products derived from this Software without
37+
* specific prior written permission.
38+
*
39+
* - Redistributions of source code must retain the above copyright
40+
* notices, this list of conditions, and the disclaimer below.
41+
*
42+
* - Redistributions in binary form must reproduce the above copyright
43+
* notice, this list of conditions, and the disclaimer below in the
44+
* documentation and/or other materials provided with the
45+
* distribution.
46+
*
47+
* THIS SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
48+
* EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO THE WARRANTIES OF
49+
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
50+
* NONINFRINGEMENT. IN NO EVENT SHALL THE CONTRIBUTORS OR COPYRIGHT
51+
* HOLDERS BE LIABLE FOR ANY CLAIM, INDIRECT, INCIDENTAL, SPECIAL,
52+
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES OR OTHER LIABILITY, WHETHER IN AN
53+
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
54+
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS WITH THE
55+
* SOFTWARE.
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* ```
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*/
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'use strict';
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// MAIN //
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/**
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* Decomposes the sequence length into its prime factors.
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*
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* @private
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* @param {number} n - length of the sequence
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* @param {Int32Array} ifac - array to store the factors
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* @param {Array<number>} ntryh - array of initial trial divisors
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* @returns {number} status code
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*/
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function decompose( n, ifac, ntryh ) {
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var ntry;
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var nl;
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var nf;
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var nq;
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var nr;
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var ib;
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var i;
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var j;
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ntry = 0;
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nl = n;
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nf = 0;
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j = 0;
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do {
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if ( j < 4 ) {
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ntry = ntryh[ j ];
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} else {
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ntry += 2;
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}
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j += 1;
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while ( true ) {
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nq = nl / ntry;
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nr = nl - (ntry * nq);
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if ( nr !== 0 ) {
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break;
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}
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nf += 1;
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ifac[ nf + 2 ] = ntry;
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nl = nq;
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if ( ntry === 2 && nf !== 1 ) {
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for ( i = 2; i <= nf; i++ ) {
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ib = nf - i + 2;
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ifac[ ib + 2 ] = ifac[ ib + 1 ];
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}
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ifac[ 3 ] = 2;
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}
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if ( nl === 1 ) {
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break;
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}
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}
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} while ( nl !== 1 );
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ifac[ 1 ] = n;
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ifac[ 2 ] = nf;
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return nf;
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}
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// EXPORTS //
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module.exports = decompose;

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