Parse a line of text into an MLlib LabeledPoint object.

def parsePoint(line):
    """
    Parse a line of text into an MLlib LabeledPoint object.
    """
    values = [float(s) for s in line.split(' ')]
    if values[0] == -1:   # Convert -1 labels to 0 for MLlib
        values[0] = 0
    return LabeledPoint(values[0], values[1:])