def createRow(calib, interval, count, countDen):
    """
    Create row to output from interval of circles c to a CSV file

    returned list includes:
    minimum radius in mm
    maximum radius in mm
    mean radius in microns
    total droplet count
    average count per area
    number density N(r)
    """
    minR = interval[0] * calib
    maxR = interval[1] * calib
    return [minR, maxR, (minR + maxR) * 500, count, countDen, countDen / (maxR - minR)]