Return an integer matrix with the Linke turbidity multiplied by 20. So it
    should be divided by 20 in before the usage (over the CPU or the GPU).

    Keyword arguments:
    date -- the datetime of the file.
    compressed -- the true value if it should return a matrix of integers or
    if it should return an uncompressed matrix of floats.

def obtain(date, compressed=True):
    """
    Return an integer matrix with the Linke turbidity multiplied by 20. So it
    should be divided by 20 in before the usage (over the CPU or the GPU).

    Keyword arguments:
    date -- the datetime of the file.
    compressed -- the true value if it should return a matrix of integers or
    if it should return an uncompressed matrix of floats.
    """
    pattern = "%s/tifs/%s_longlat_wgs84.tif"
    ds = gdal.Open(pattern % (localpath, str(date.month).zfill(2)))
    linke = ds.ReadAsArray()
    return linke if compressed else linke / 20.