DataFilters.js

/*
  Dave_js.data_filters is a collection of filters and data manipulation tools.
  This is a singleton and can not be instantiated 
  like most of of the Dave_js packages.
*/

Dave_js.data_filters = {
  //Moving Average Filter
  //Arguments:
  //   numOfPts: number of points in front of and behind the current point
  //             to average.
  //   dataSet:  Reference to array of points to filter
  //Output:
  //   Returns the filtered dataset
  movingAve : function(numOfSamples, dataSet){
    var out = [];
    var sum, negOff, posOff, cnt;

    for (var pt_i = 0; pt_i < dataSet.length; pt_i++) {
      if (isNaN(+dataSet[pt_i])) {continue;}

      sum = +dataSet[pt_i];
      cnt = 1;
      for (var offset = 1; offset < numOfSamples; offset++) {
        negOff = pt_i - offset;
        posOff = pt_i + offset;

        if (negOff > 0 && !isNaN(dataSet[negOff])) {
          sum += +dataSet[negOff];
          cnt++;
        }
        if (posOff < dataSet.length && !isNaN(dataSet[posOff])) {
          sum += +dataSet[posOff];
          cnt++;
        }
      }
      out[pt_i] = sum / cnt;
    }
    return out;
  }
};