80 lines
2.8 KiB
C++
80 lines
2.8 KiB
C++
/********************************************************
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* ██████╗ ██████╗████████╗██╗
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* ██╔════╝ ██╔════╝╚══██╔══╝██║
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* ██║ ███╗██║ ██║ ██║
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* ██║ ██║██║ ██║ ██║
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* ╚██████╔╝╚██████╗ ██║ ███████╗
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* ╚═════╝ ╚═════╝ ╚═╝ ╚══════╝
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* Geophysical Computational Tools & Library (GCTL)
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*
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* Copyright (c) 2023 Yi Zhang (yizhang-geo@zju.edu.cn)
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*
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* GCTL is distributed under a dual licensing scheme. You can redistribute
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* it and/or modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation, either version 2
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* of the License, or (at your option) any later version. You should have
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* received a copy of the GNU Lesser General Public License along with this
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* program. If not, see <http://www.gnu.org/licenses/>.
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*
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* If the terms and conditions of the LGPL v.2. would prevent you from using
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* the GCTL, please consider the option to obtain a commercial license for a
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* fee. These licenses are offered by the GCTL's original author. As a rule,
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* licenses are provided "as-is", unlimited in time for a one time fee. Please
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* send corresponding requests to: yizhang-geo@zju.edu.cn. Please do not forget
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* to include some description of your company and the realm of its activities.
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* Also add information on how to contact you by electronic and paper mail.
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******************************************************/
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#include "windowfunc.h"
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void gctl::window_hamming(int taps, array<double> &coeff)
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{
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double alpha = 0.54;
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double beta = 0.46;
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coeff.resize(taps);
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for(int i = 0; i < taps; i++)
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{
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coeff[i] = alpha - beta * cos(2.0 * M_PI * i / (taps - 1));
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}
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return;
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}
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void gctl::window_hanning(int taps, array<double> &coeff)
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{
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coeff.resize(taps);
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for(int i = 0; i < taps; i++)
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{
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coeff[i] = sin(((double) M_PI * i) / (taps - 1)) *
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sin(((double) M_PI * i) / (taps - 1));
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}
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return;
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}
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void gctl::window_triangle(int taps, array<double> &coeff)
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{
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double l = taps;
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coeff.resize(taps);
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for(int i = 0; i < taps; i++)
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{
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coeff[i] = 1 - abs((i - (((double)(taps-1)) / 2.0)) / (((double)l) / 2.0));
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}
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return;
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}
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void gctl::window_blackman(int taps, array<double> &coeff)
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{
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double alpha0 = 0.42;
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double alpha1 = 0.5;
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double alpha2 = 0.08;
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coeff.resize(taps);
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for(int i = 0; i < taps; i++)
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{
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coeff[i] = alpha0 - alpha1 * cos(2.0 * M_PI * i / (taps - 1))
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- alpha2 * cos(4.0 * M_PI * i / (taps - 1));
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}
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return;
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} |