// file: $SPEECH_HOMEWORK4/hw4/class/snr_ratio/v1.0/snr_pdf_1.cc
//

// isip include files
//
#include "signal_noise_ratio.h"
#include "signal_noise_ratio_constants.h"

// method: calculate_pdf_cc
//
// arguments:
//  float_4** energy (input) the energy signal
//  int_4 num_energy (input) the total number of energy signals
//  int_4** pdf (output) the output location for the pdf values
//  float_4** mean (output) the mean of the channel
//  float_4* min (input) the minimum value of each channel
//  float_4* max (input) the maximum value of each channel
//
// return: a logical_1 indicating status
//
logical_1 Signal::calculate_pdf_cc (float_4** energy_a, int_4 num_energy_a,
				    int_4** pdf_a, float_4** mean_a,
				    float_4* min_a, float_4* max_a) {

  // check argument
  //
  if (pdf_a == (int_4**)NULL) {
    error_handler_cc((char_1*)"calculate_pdf_cc",
		     (char_1*)"output memory is not allocated");
  }

  // loop over channels
  //
  for (int_4 channel=0;channel<num_chans_d;channel++) {

    // generate bin width according to number of bins
    //
    float_4 bin_width = (max_a[channel] - min_a[channel]) / num_bins_d;

    // loop over data
    //

    for (int_4 data=0;data<num_energy_a;data++) {

      // check for equivalence of the last element
      //
      if (energy_a[data][channel] == max_a[channel]) {
	pdf_a[num_bins_d - 1][channel]++;
	mean_a[num_bins_d -1][channel] += energy_a[data][channel];
      }

      // put in the correct bin
      //
      else {

	int_4 bin_num = (int_4) ((energy_a[data][channel] - min_a[channel])
	  / bin_width);

	pdf_a[bin_num][channel]++;
	mean_a[bin_num][channel] += energy_a[data][channel];
      }
    }
  }

  // generate the mean values
  //
  for (int_4 channel=0;channel<num_chans_d;channel++) {
    for (int_4 bin=0;bin<num_bins_d;bin++) {
      if (pdf_a[bin][channel] == 0) {
	mean_a[bin][channel] = (((max_a[channel]-min_a[channel])/num_bins_d)
				* (2*bin+1)/2)+min_a[channel];
      }
      else {
	mean_a[bin][channel] /= pdf_a[bin][channel];
      }
    }
  }

  if (debug_level_d > 1) {
    for (int_4 i=0; i<num_chans_d;i++) {
      for (int_4 j=0; j<num_bins_d; j++ ) {
	fprintf(stdout, "chan %ld :: bin [%ld] :: freq = %ld value = %.2f\n",
                i, j, pdf_a[j][i], mean_a[j][i]);
      }
    }
  }
  
  // exit gracefully
  //
  return ISIP_TRUE;
}