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());

  }

}