def pass_floats(output_string):
    """Parse AFNI command STDOUT output strings and return the output values 
    as a list of floats.

    :type output_string: str
    :param output_string: An AFNI command standard output.
    :rtype: list
    :return: A list of float values.
    """

    lines = output_string.splitlines()
    values_list = []

    for l in lines:
        try:
            val = float(l)
            values_list.append(val)
        except:
            pass

    return values_list