compress-linear-interpolation-ciq

// use standard linear interpolation
function compressArrayData2(data as Array<Numeric>, dataSize as Number, newSize as Number)  as Array<Numeric> {
    //if (newSize >= data.size()) {
    if (newSize >= dataSize) {
        return data;
    }

    // bucketSize > 1. e.g. if data.size() is 480 and newSize is 240, bucket size is 2
    //var bucketSize = data.size() * 1.0 / newSize;
    var bucketSize = dataSize * 1.0 / newSize;
    var outputArray = new Array<Numeric>[newSize];

    var positionInInput = 0.0;
    // linear interpolation
    for (var i = 0; i < newSize; i++) {
        if (positionInInput == positionInInput.toNumber()) {
            // use exact data point
            outputArray[i] = data[positionInInput.toNumber()];
        }  else {
            // interpolate
            var x = positionInInput;
            var x0 = positionInInput.toNumber();
            var x1 = Math.round(positionInInput + 0.5).toNumber();
            var y0 = data[x0];
            var y1 = data[x1];

            outputArray[i] = y0 * ((x1 - x).toFloat() / (x1 - x0)) + y1 * ((x - x0).toFloat() / (x1 - x0));
        }
        positionInInput += bucketSize;
    }
    return outputArray;
}