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gunjjoshigunjjoshi
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feat: add passf4
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4 files changed

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‎lib/node_modules/@stdlib/fft/base/fftpack/lib/c2_ref.js‎

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* @private
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* @param {number} a1 - index of first dimension
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* @param {number} a2 - index of second dimension
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* @param {Float64Array} c2 - secondary intermediate array for FFT computations
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* @param {number} idl1 - stride related to the `l1` parameter
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* @returns {number} - calculated index
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*/

‎lib/node_modules/@stdlib/fft/base/fftpack/lib/passf2.js‎

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@@ -92,7 +92,7 @@ function passf2( ido, l1, cc, ch, wa1 ) {
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cc_offset = 1 + ( ido * 3 );
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// Function body:
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if ( ido == 2 ) {
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if ( ido === 2 ) {
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for ( k = 1; k <= l1; ++k ) {
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ch[ chRef( 1, k, 1, l1, ido ) - ch_offset ] = cc[ ccRef( 1, 1, k, 2, ido ) - cc_offset ] + cc[ ccRef( 1, 2, k, 2, ido ) - cc_offset ];
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ch[ chRef( 1, k, 2, l1, ido ) - ch_offset ] = cc[ ccRef( 1, 1, k, 2, ido ) - cc_offset ] - cc[ ccRef( 1, 2, k, 2, ido ) - cc_offset ];

‎lib/node_modules/@stdlib/fft/base/fftpack/lib/passf3.js‎

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@@ -107,7 +107,7 @@ function passf3( ido, l1, cc, ch, wa1, wa2 ) {
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cc_offset = 1 + ( ido << 2 );
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// Function body:
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if ( ido == 2 ) {
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if ( ido === 2 ) {
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for ( k = 1; k <= l1; ++k ) {
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tr2 = cc[ ccRef( 1, 2, k, 3, ido ) - cc_offset ] + cc[ ccRef( 1, 3, k, 3, ido ) - cc_offset ];
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cr2 = cc[ ccRef( 1, 1, k, 3, ido ) - cc_offset ] + ( taur * tr2 );

‎lib/node_modules/@stdlib/fft/base/fftpack/lib/passf4.js‎

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/**
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* @license Apache-2.0
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*
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* Copyright (c) 2024 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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/* eslint-disable max-len */
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'use strict';
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// MODULES //
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var chRef = require( '@stdlib/fft/base/fftpack/lib/ch_ref.js' );
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var ccRef = require( '@stdlib/fft/base/fftpack/lib/cc_ref.js' );
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// MAIN //
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/**
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* Performs a pass of length 4 of the FFT algorithm.
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*
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* @private
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* @param {integer} ido - number of real values for each transform
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* @param {integer} l1 - length of the input sequences
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* @param {Float64Array} cc - input array containing sequences to be transformed
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* @param {Float64Array} ch - output array containing transformed sequences
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* @param {Float64Array} wa1 - first array of twiddle factors
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* @param {Float64Array} wa2 - second array of twiddle factors
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* @param {Float64Array} wa3 - third array of twiddle factors
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* @returns {void}
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*/
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function passf4( ido, l1, cc, ch, wa1, wa2, wa3 ) {
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var ch_offset;
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var cc_offset;
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var ci2;
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var ci3;
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var ci4;
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var cr2;
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var cr3;
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var cr4;
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var ti1;
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var ti2;
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var ti3;
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var ti4;
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var tr1;
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var tr2;
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var tr3;
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var tr4;
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var i;
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var k;
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// Parameter adjustments...
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ch_offset = 1 + ( ido * ( 1 + l1 ) );
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cc_offset = 1 + ( ido * 5 );
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// Function body:
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if ( ido === 2 ) {
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for ( k = 1; k <= l1; ++k ) {
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ti1 = cc[ ccRef( 2, 1, k, 4, ido ) - cc_offset ] - cc[ ccRef( 2, 3, k, 4, ido ) - cc_offset ];
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ti2 = cc[ ccRef( 2, 1, k, 4, ido ) - cc_offset ] + cc[ ccRef( 2, 3, k, 4, ido ) - cc_offset ];
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tr4 = cc[ ccRef( 2, 2, k, 4, ido ) - cc_offset ] - cc[ ccRef( 2, 4, k, 4, ido ) - cc_offset ];
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ti3 = cc[ ccRef( 2, 2, k, 4, ido ) - cc_offset ] + cc[ ccRef( 2, 4, k, 4, ido ) - cc_offset ];
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tr1 = cc[ ccRef( 1, 1, k, 4, ido ) - cc_offset ] - cc[ ccRef( 1, 3, k, 4, ido ) - cc_offset ];
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tr2 = cc[ ccRef( 1, 1, k, 4, ido ) - cc_offset ] + cc[ ccRef( 1, 3, k, 4, ido ) - cc_offset ];
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ti4 = cc[ ccRef( 1, 4, k, 4, ido ) - cc_offset ] - cc[ ccRef( 1, 2, k, 4, ido ) - cc_offset ];
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tr3 = cc[ ccRef( 1, 2, k, 4, ido ) - cc_offset ] + cc[ ccRef( 1, 4, k, 4, ido ) - cc_offset ];
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ch[ chRef( 1, k, 1, l1, ido ) - ch_offset ] = tr2 + tr3;
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ch[ chRef( 1, k, 3, l1, ido ) - ch_offset ] = tr2 - tr3;
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ch[ chRef( 2, k, 1, l1, ido ) - ch_offset ] = ti2 + ti3;
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ch[ chRef( 2, k, 3, l1, ido ) - ch_offset ] = ti2 - ti3;
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ch[ chRef( 1, k, 2, l1, ido ) - ch_offset ] = tr1 + tr4;
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ch[ chRef( 1, k, 4, l1, ido ) - ch_offset ] = tr1 - tr4;
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ch[ chRef( 2, k, 2, l1, ido ) - ch_offset ] = ti1 + ti4;
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ch[ chRef( 2, k, 4, l1, ido ) - ch_offset ] = ti1 - ti4;
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}
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} else {
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for ( k = 1; k <= l1; ++k ) {
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for ( i = 2; i <= ido; i += 2 ) {
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ti1 = cc[ ccRef( i, 1, k, 4, ido ) - cc_offset ] - cc[ ccRef( i, 3, k, 4, ido ) - cc_offset ];
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ti2 = cc[ ccRef( i, 1, k, 4, ido ) - cc_offset ] + cc[ ccRef( i, 3, k, 4, ido ) - cc_offset ];
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ti3 = cc[ ccRef( i, 2, k, 4, ido ) - cc_offset ] + cc[ ccRef( i, 4, k, 4, ido ) - cc_offset ];
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tr4 = cc[ ccRef( i, 2, k, 4, ido ) - cc_offset ] - cc[ ccRef( i, 4, k, 4, ido ) - cc_offset ];
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tr1 = cc[ ccRef( i - 1, 1, k, 4, ido ) - cc_offset ] - cc[ ccRef( i - 1, 3, k, 4, ido ) - cc_offset ];
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tr2 = cc[ ccRef( i - 1, 1, k, 4, ido ) - cc_offset ] + cc[ ccRef( i - 1, 3, k, 4, ido ) - cc_offset ];
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ti4 = cc[ ccRef( i - 1, 4, k, 4, ido ) - cc_offset ] - cc[ ccRef( i - 1, 2, k, 4, ido ) - cc_offset ];
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tr3 = cc[ ccRef( i - 1, 2, k, 4, ido ) - cc_offset ] + cc[ ccRef( i - 1, 4, k, 4, ido ) - cc_offset ];
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ch[ chRef( i - 1, k, 1, l1, ido ) - ch_offset ] = tr2 + tr3;
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cr3 = tr2 - tr3;
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ch[ chRef( i, k, 1, l1, ido ) - ch_offset ] = ti2 + ti3;
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ci3 = ti2 - ti3;
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cr2 = tr1 + tr4;
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cr4 = tr1 - tr4;
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ci2 = ti1 + ti4;
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ci4 = ti1 - ti4;
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ch[ chRef( i - 1, k, 2, l1, ido ) - ch_offset ] = ( wa1[ i - 1 - 1 ] * cr2 ) + ( wa1[ i - 1 ] * ci2 );
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ch[ chRef( i, k, 2, l1, ido ) - ch_offset ] = ( wa1[ i - 1 - 1 ] * ci2 ) - ( wa1[ i - 1 ] * cr2 );
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ch[ chRef( i - 1, k, 3, l1, ido ) - ch_offset ] = ( wa2[ i - 1 - 1 ] * cr3 ) + ( wa2[ i - 1 ] * ci3 );
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ch[ chRef( i, k, 3, l1, ido ) - ch_offset ] = ( wa2[ i - 1 - 1 ] * ci3 ) - ( wa2[ i - 1 ] * cr3 );
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ch[ chRef( i - 1, k, 4, l1, ido ) - ch_offset ] = ( wa3[ i - 1 - 1 ] * cr4 ) + ( wa3[ i - 1 ] * ci4 );
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ch[ chRef( i, k, 4, l1, ido ) - ch_offset ] = ( wa3[ i - 1 - 1 ] * ci4 ) - ( wa3[ i - 1 ] * cr4 );
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}
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}
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}
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}
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// EXPORTS //
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module.exports = passf4;

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