samples.cc

题描述的是一个旅行商要到几个城市去

/* $Id: samples.cc,v 1.2 2006-08-09 15:20:54 jonathan Exp $
 * Jonathan Ledlie, Harvard University.
 * Copyright 2005.  All rights reserved.
 */

#include "sim.h"
#include "samples.h"

int PING_HISTORY_COUNT = 4;
double PING_SAMPLE_PERCENTILE = .25;
int MIN_HISTORY_COUNT = 0;

Samples::Samples() {
  ewma = 0;
  jitterCount = 0;
  weightedError = 0;
  vec = new Point ();
  appVector = new Point ();
}

Samples::~Samples() {
  delete vec;
  delete appVector;
}

void Samples::addSample (double sample, int myId, int yourId, 
                           Point *yourCoord, double yourWeightedError,
                           Point *yourAppCoord, int timestamp) {
  stamp = timestamp;

  if (PING_HISTORY_COUNT == -1) {
    ewma = PING_SAMPLE_PERCENTILE * sample +
      (1.-PING_SAMPLE_PERCENTILE) + ewma;
    sample = ewma;
  }

  weightedError = yourWeightedError;
  vec->assign (yourCoord);
  appVector->assign (yourAppCoord);

  // toss the sample from the front
  if (samples.size() > PING_HISTORY_COUNT)
    samples.pop_front ();
  // add this guy to the back
  samples.push_back (sample);
}

double Samples::getSample () {

  if (samples.size() > MIN_HISTORY_COUNT) {
    // sort em
    deque<double> sortedSamples (samples);
    sort (sortedSamples.begin(), sortedSamples.end());

    int percentile = (int)(samples.size() * PING_SAMPLE_PERCENTILE);
    double sample_at_percentile = sortedSamples[percentile];

    return sample_at_percentile;
  } else {
    return -1;
  }
}

void Samples::print () {
  printf ("sample size %d\n", samples.size());
  for (int i = 0; i < samples.size(); i++) {
    printf ("sample %d %f\n", i, samples[i]);
  }
}

ostream& operator << (ostream& os, Samples *s) {
  os << "[sC " << s->vec << " aC " << s->appVector 
     << " wE " << s->weightedError << " s ";
  for (int i = 0; i < s->samples.size(); i++) {
    os << s->samples[i] << " ";
  } 
  os << "]";
  return os;
}