def _MINIDX(x, p=0):
    """
    Delivers the index to an array which corresponds to `_minperiod` offset by
    `p`. This allow direct manipulation of single values in arrays like in the
    `obv` scenario in which a seed value is needed for the 1st delivered value
    (in `ta-lib` mode) because no `close` to `previous close` comparison is
    possible.
    """
    return x._minperiod - 1 + p
