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signalUtil.cpp

Go to the documentation of this file.

#include <math.h>
#include <stdio.h>

#include "signalUtil.h"


void signalUtil::gen_freqMix( double *vecX, double *vecY, size_t N)
{
  const double PI = 3.1415926535897932384626433832795;
  const double range = 2 * PI;
  const double incr = range / (double)N;

  double point = 0.0;
  int i;
  for (i = 0; i < N; i++) {
    vecX[i] = point;
    vecY[i] = 4 * sin( 64 * point ) + 
              2 * sin( 32 * point ) + 
              1 * sin( 16 * point ) +
            0.5 * sin( 8  * point );
    // printf("%7.4g, %7.4g\n", vecX[i], vecY[i] );
    point = point + incr;
  }
} // gen_freqMix



void signalUtil::gen_sinCombo( double *vecX, double *vecY, size_t N )
{
  const double PI = 3.1415926535897932384626433832795;
  const double range = 1 * PI;
  const double incr = range / (double)N;

  double point = 0.0;

  int stepCnt = 0;
  int i;
  for (i = 0; i < N; i++) {
    vecX[i] = point;
    // vecY[i] = sin( 64 * point ) + sin( 32 * point ) + sin( 16 * point ); 
    // vecY[i] = sin( 16 * PI * point ) + sin( 4 * PI * point ); 
    vecY[i] = sin( 4 * PI * point ); 

    // printf("x[%2d] = %7.4g, y[%2d] = %7.4g\n", i, vecX[i], i, vecY[i] );
    // printf("%7.4g, %7.4g\n", vecX[i], vecY[i] );
    // printf("%d, %7.4g\n", i, vecY[i] );

    point = point + incr;
  }
}

double signalUtil::new_y( size_t x1, double y1, 
                          size_t x2, double y2,
                          size_t newX )
{
  double newY = 0.0;

  newY = (((y2 - y1)/(x2 - x1)) * (newX - x1)) + y1;
  return newY;
} // new_y


void signalUtil::sawToothWave( double *vec,
                               size_t N,
                               size_t numCycles,
                               double amplitude )
{
  size_t spacing = N / numCycles;
  size_t step = spacing / 4;
  bool positive = true;

  size_t x1, x2;
  double y1, y2;

  for (size_t i = 0; i < N; i = i + spacing) {
    x1 = i;
    x2 = i + step;
    for (size_t j = 1; j <= 4; j++) {
      switch (j) {
        case 1: {
          y1 = 0.0;
          y2 = amplitude;
        }
        break;
        case 2:{
          y1 = amplitude;
          y2 = 0.0;
        }
        break;
        case 3:{
          y1 = 0.0;
          y2 = -amplitude;
        }
        break;
        case 4:{
          y1 = -amplitude;
          y2 = 0.0;
        }
        break;
      } // switch
      vec[x1] = y1;
      for (size_t k = x1+1; k < x2; k++) {
        vec[k] = new_y( x1, y1, x2, y2, k );
      }
      x1 = x2;
      x2 = x2 + step;
    }
  }
} // sawToothWave



void signalUtil::addSignal( double *C, 
                            const double *A,
                            const double *B,
                            const size_t N )
{
  for (size_t i = 0; i < N; i++) {
    C[i] = A[i] + B[i];
  }
}


void signalUtil::prCoords( double *vecX, double *vecY, size_t len )
{
  for (int i = 0; i < len; i++) {
    printf("%7.4f  %7.4f\n", vecX[i], vecY[i] );
  }
}


void signalUtil::prVec( double *vec, size_t len )
{
  for (int i = 0; i < len; i++) {
    printf("%4d  %7.4f\n", i, vec[i] );
  }
} // prVec



bool signalUtil::vecEqual( const double *d1,
                           const double *d2,
                           const size_t N )
{
  bool rslt = true;

  for (size_t i = 0; i < N; i++) {
    if (d1[i] != d2[i]) {
      rslt = false;
      break;
    }
  }
  return rslt;
}

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