def dip_direction2strike(azimuth):
    """
    Converts a planar measurment of dip direction using the dip-azimuth
    convention into a strike using the right-hand-rule.

    Parameters
    ----------
    azimuth : number or string
        The dip direction of the plane in degrees. This can be either a
        numerical azimuth in the 0-360 range or a string representing a quadrant
        measurement (e.g. N30W).

    Returns
    -------
    strike : number
        The strike of the plane in degrees following the right-hand-rule.
    """
    azimuth = parse_azimuth(azimuth)
    strike = azimuth - 90
    if strike < 0:
        strike += 360
    return strike
Converts a planar measurment of dip direction using the dip-azimuth
    convention into a strike using the right-hand-rule.

    Parameters
    ----------
    azimuth : number or string
        The dip direction of the plane in degrees. This can be either a
        numerical azimuth in the 0-360 range or a string representing a quadrant
        measurement (e.g. N30W).

    Returns
    -------
    strike : number
        The strike of the plane in degrees following the right-hand-rule.