Unidata / MetPy

        return x[0], y[0]

@exporter.export

@check_units('[pressure]', '[temperature]', '[temperature]')

def el(pressure, temperature, dewpt):

    r"""Calculate the equilibrium level.

    This works by finding the last intersection of the ideal parcel path and

    the measured environmental temperature. If there is one or fewer intersections, there is

    no equilibrium level.

    Parameters

    ----------

    pressure : `pint.Quantity`

        The atmospheric pressure

    temperature : `pint.Quantity`

        The temperature at the levels given by `pressure`

    dewpt : `pint.Quantity`

        The dew point at the levels given by `pressure`

    Returns

    -------

    `pint.Quantity, pint.Quantity`

        The EL pressure and temperature

    See Also

    --------

    parcel_profile

    """

    ideal_profile = parcel_profile(pressure, temperature[0], dewpt[0]).to('degC')

    x, y = find_intersections(pressure[1:], ideal_profile[1:], temperature[1:])

    # If there is only one intersection, there are two possibilities:

    # the dataset does not contain the EL, or the LFC = LCL.

    if len(x) <= 1:

        if (ideal_profile[-1] < temperature[-1]) and (len(x) == 1):

            # Profile top colder than environment with one

            # intersection, EL exists and LFC = LCL

            return x[-1], y[-1]

        else:

            # The EL does not exist, either due to incomplete data

            # or no intersection occurring.

            return np.nan * pressure.units, np.nan * temperature.units

    else:

        return x[-1], y[-1]

@exporter.export

    return lcl_p, dewpoint(vapor_pressure(lcl_p, w))

@exporter.export

@check_units('[pressure]', '[temperature]', '[temperature]')

def lfc(pressure, temperature, dewpt):

    r"""Calculate the level of free convection (LFC).

    This works by finding the first intersection of the ideal parcel path and

    the measured parcel temperature.

    Parameters

    ----------

    pressure : `pint.Quantity`

        The atmospheric pressure

    temperature : `pint.Quantity`

        The temperature at the levels given by `pressure`

    dewpt : `pint.Quantity`

        The dew point at the levels given by `pressure`

    Returns

    -------

    `pint.Quantity`

        The LFC pressure and temperature

    See Also

    --------

    parcel_profile

    """

    ideal_profile = parcel_profile(pressure, temperature[0], dewpt[0]).to('degC')

    # The parcel profile and data have the same first data point, so we ignore

    # that point to get the real first intersection for the LFC calculation.

    x, y = find_intersections(pressure[1:], ideal_profile[1:], temperature[1:],

                              direction='increasing')

    # Two possible cases here: LFC = LCL, or LFC doesn't exist

    if len(x) == 0:

        if np.any(ideal_profile > temperature):

            # LFC = LCL

            x, y = lcl(pressure[0], temperature[0], dewpt[0])

            return x, y

        # LFC doesn't exist

        else:

            return np.nan * pressure.units, np.nan * temperature.units

    else:

        return x[0], y[0]

@exporter.export