ar_spec.cpp
上传用户：jtjnyq9001
上传日期：2014-11-21
资源大小：3974k
文件大小：2k
- //
- // File = arspec.cpp
- //
- #include <fstream>
- #include "ar_spec.h"
- #include "misdefs.h"
- using namespace std;
- //==============================================
- // constructor
- ArSpectrum::ArSpectrum( int ar_order,
- double* ar_coeff,
- double samp_intvl,
- double drv_var,
- int num_pts,
- double max_freq)
- {
- double denom, two_pi_f, psd_val;
- double a_func_real, a_func_imag;
- int f_idx, cof_idx;
- Samp_Intvl = samp_intvl;
- Num_Pts = num_pts;
- Spec_Buf = new double[Num_Pts];
- Max_Freq = max_freq;
- Freq_Delt = Max_Freq*Samp_Intvl/double(Num_Pts-1);
- double total_pwr = 0.0;
- for(f_idx=0; f_idx<Num_Pts; f_idx++)
- {
- a_func_real = 0.0;
- a_func_imag = 0.0;
- two_pi_f = TWO_PI * f_idx * Freq_Delt;
- for(cof_idx=0; cof_idx<=ar_order; cof_idx++)
- {
- a_func_real += (ar_coeff[cof_idx]*cos(cof_idx*two_pi_f));
- a_func_imag -= (ar_coeff[cof_idx]*sin(cof_idx*two_pi_f));
- }
- denom = a_func_real*a_func_real + a_func_imag*a_func_imag;
- psd_val = samp_intvl*drv_var/denom;
- total_pwr += psd_val;
- Spec_Buf[f_idx] = psd_val;
- }
- return;
- }
- //------------------------
- // destructor
- ArSpectrum::~ArSpectrum(void){};
- void ArSpectrum::DumpSpectrum( char* out_file_nam,
- bool db_plot_enab )
- {
- int i;
- double freq, vert_offset;
- ofstream out_file(out_file_nam, ios::out);
- vert_offset = 10.0 * log10(Spec_Buf[0]);
- for(i=0; i<Num_Pts; i++)
- {
- freq = i*Freq_Delt/Samp_Intvl;
- if( db_plot_enab) {
- out_file << freq << ", "
- << ((10.0 * log10(Spec_Buf[i]))-vert_offset)
- << endl;
- }
- else {
- out_file << freq << ", " << (Spec_Buf[i])
- << endl;
- }
- }
- out_file.close();
- }
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