sclass CompressToInterpolatedDoubleArray {
  // raw data to compress (integers)
  int[] data;
  
  // output
  InterpolatedDoubleArray result;
  
  // options
  settable double slopeTolerance = 0.01;
  
  // internal
  new IntBuffer indices;
  new DoubleBuffer values;
  
  *(int[] *data) {}
  
  InterpolatedDoubleArray get() {
    int iData = 0;
    while (iData < data.length) {
      int startValue = data[iData];
      // possible range of actual floating point starting value
      DoubleRange startValueRange = doubleRange(startValue-0.5, startValue+0.5);
      
      // see how far the straight line goes from iData
      DoubleRange totalSlopeRange = null;
      int jData; // our straight line ends at jData-1
      for (jData = iData+1; jData < data.length; jData++) {
        double x = data[jData], h = jData-iData;
        
        // possible range of actual floating point value
        DoubleRange xRange = doubleRange(x-0.5, x+0.5);
        
        // most generous range for possible slope depending
        // on possible floating point values at start and end
        DoubleRange slopeRange = doubleRange(
          (xRange.start-startValueRange.end)/h,
          (xRange.end-startValueRange.start)/h);
        
        // grow range a little to avoid size 0 ranges
        slopeRange = growRange(slopeTolerance, slopeRange);
        //printVars(+iData, +jData, +slopeRange, +totalSlopeRange);
        if (totalSlopeRange == null)
          totalSlopeRange = slopeRange;
        else {
          slopeRange = intersectRanges(slopeRange, totalSlopeRange);
          if (empty(slopeRange))
            break;
          else
            totalSlopeRange = slopeRange;
        }
      }
      indices.add(iData);
      values.add(data[iData]);
      iData = max(iData+1, jData-1);
    }
    
    ret result = new InterpolatedDoubleArray(indices.toArrayNonNull(), values.toArrayNonNull());
  }
}