please explain how it works
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could anyone tell me briefly how this code is working?please help me.
// nonrec_t.spc -- test program for non-recursive filter design #include "tools.h" #include "ltisys.h" #include "nonrec.h" int main() { Graph gr(3,2,"Non-Recursive Filter Design"); // calculate low-pass filter and plot LTISystem lp = NRLowPass(0.1,63); lp.a.plot(gr,1,"Low-pass at 0.1","Samples","Amp"); // calculate frequency response and plot Spectrum lpf(500,1000); for (int i=0;i<500;i++) lpf[i] = lp.response(i/1000.0); lpf.plotLogMag(gr,2,"Frequency Response"); // calculate high-pass filter and plot LTISystem hp = NRHighPass(0.4,63); hp.a.plot(gr,3,"High-pass at 0.4","Samples","Amp"); // calculate frequency response and plot Spectrum hpf(500,1000); for (int i=0;i<500;i++) hpf[i] = hp.response(i/1000.0); hpf.plotLogMag(gr,4,"Frequency Response"); // calculate band-pass filter and plot LTISystem bp = NRBandPass(0.2,0.3,63); bp.a.plot(gr,5,"Band-pass at 0.2-0.3","Samples","Amp"); // calculate frequency response and plot Spectrum bpf(500,1000); for (int i=0;i<500;i++) bpf[i] = bp.response(i/1000.0); bpf.plotLogMag(gr,6,"Frequency Response"); gr.close(); }// kaiser_t.cpp -- test program for Kaiser window design #include "tools.h" #include "ltisys.h" #include "nonrec.h" #include "kaiser.h" const int MAXKAISERWIN=256; // maximum window length // Create non-recursive low-pass filter using Kaiser window LTISystem KaiserLowPass( double freq, // corner freq // (fraction of sampling rate) double ripple, // allowed ripple (dB) double twidth // transition width // (fraction of sampling rate) } ) // returns LTI System { int i; // get (half-)Kaiser window Waveform kwin = Kaiser(ripple,twidth,MAXKAISERWIN); int nhalf = kwin.count()-1; // generate one half of coefficients from // windowed sinc() function double omega = 2*PI*freq; for (i=0;i<=nhalf;i++) kwin[i+1] *= omega*sinc(i*omega)/PI; // copy into LT -
could anyone tell me briefly how this code is working?please help me.
// nonrec_t.spc -- test program for non-recursive filter design #include "tools.h" #include "ltisys.h" #include "nonrec.h" int main() { Graph gr(3,2,"Non-Recursive Filter Design"); // calculate low-pass filter and plot LTISystem lp = NRLowPass(0.1,63); lp.a.plot(gr,1,"Low-pass at 0.1","Samples","Amp"); // calculate frequency response and plot Spectrum lpf(500,1000); for (int i=0;i<500;i++) lpf[i] = lp.response(i/1000.0); lpf.plotLogMag(gr,2,"Frequency Response"); // calculate high-pass filter and plot LTISystem hp = NRHighPass(0.4,63); hp.a.plot(gr,3,"High-pass at 0.4","Samples","Amp"); // calculate frequency response and plot Spectrum hpf(500,1000); for (int i=0;i<500;i++) hpf[i] = hp.response(i/1000.0); hpf.plotLogMag(gr,4,"Frequency Response"); // calculate band-pass filter and plot LTISystem bp = NRBandPass(0.2,0.3,63); bp.a.plot(gr,5,"Band-pass at 0.2-0.3","Samples","Amp"); // calculate frequency response and plot Spectrum bpf(500,1000); for (int i=0;i<500;i++) bpf[i] = bp.response(i/1000.0); bpf.plotLogMag(gr,6,"Frequency Response"); gr.close(); }// kaiser_t.cpp -- test program for Kaiser window design #include "tools.h" #include "ltisys.h" #include "nonrec.h" #include "kaiser.h" const int MAXKAISERWIN=256; // maximum window length // Create non-recursive low-pass filter using Kaiser window LTISystem KaiserLowPass( double freq, // corner freq // (fraction of sampling rate) double ripple, // allowed ripple (dB) double twidth // transition width // (fraction of sampling rate) } ) // returns LTI System { int i; // get (half-)Kaiser window Waveform kwin = Kaiser(ripple,twidth,MAXKAISERWIN); int nhalf = kwin.count()-1; // generate one half of coefficients from // windowed sinc() function double omega = 2*PI*freq; for (i=0;i<=nhalf;i++) kwin[i+1] *= omega*sinc(i*omega)/PI; // copy into LTTry reading the article you copied this from: http://www.phon.ucl.ac.uk/courses/spsci/dsp/lpc.html[^] If you don't understand digital signal processing, learn that first.
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could anyone tell me briefly how this code is working?please help me.
// nonrec_t.spc -- test program for non-recursive filter design #include "tools.h" #include "ltisys.h" #include "nonrec.h" int main() { Graph gr(3,2,"Non-Recursive Filter Design"); // calculate low-pass filter and plot LTISystem lp = NRLowPass(0.1,63); lp.a.plot(gr,1,"Low-pass at 0.1","Samples","Amp"); // calculate frequency response and plot Spectrum lpf(500,1000); for (int i=0;i<500;i++) lpf[i] = lp.response(i/1000.0); lpf.plotLogMag(gr,2,"Frequency Response"); // calculate high-pass filter and plot LTISystem hp = NRHighPass(0.4,63); hp.a.plot(gr,3,"High-pass at 0.4","Samples","Amp"); // calculate frequency response and plot Spectrum hpf(500,1000); for (int i=0;i<500;i++) hpf[i] = hp.response(i/1000.0); hpf.plotLogMag(gr,4,"Frequency Response"); // calculate band-pass filter and plot LTISystem bp = NRBandPass(0.2,0.3,63); bp.a.plot(gr,5,"Band-pass at 0.2-0.3","Samples","Amp"); // calculate frequency response and plot Spectrum bpf(500,1000); for (int i=0;i<500;i++) bpf[i] = bp.response(i/1000.0); bpf.plotLogMag(gr,6,"Frequency Response"); gr.close(); }// kaiser_t.cpp -- test program for Kaiser window design #include "tools.h" #include "ltisys.h" #include "nonrec.h" #include "kaiser.h" const int MAXKAISERWIN=256; // maximum window length // Create non-recursive low-pass filter using Kaiser window LTISystem KaiserLowPass( double freq, // corner freq // (fraction of sampling rate) double ripple, // allowed ripple (dB) double twidth // transition width // (fraction of sampling rate) } ) // returns LTI System { int i; // get (half-)Kaiser window Waveform kwin = Kaiser(ripple,twidth,MAXKAISERWIN); int nhalf = kwin.count()-1; // generate one half of coefficients from // windowed sinc() function double omega = 2*PI*freq; for (i=0;i<=nhalf;i++) kwin[i+1] *= omega*sinc(i*omega)/PI; // copy into LTashwiny wrote:
could anyone tell me briefly how this code is working?
Which part exactly?
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