Unidata / MetPy

    temperature = np.array([22.2, 14.6, 12., 9.4, 7., -38.]) * units.celsius

    dewpoint = np.array([19., -11.2, -10.8, -10.4, -10., -53.2]) * units.celsius

    parcel_prof = parcel_profile(p, temperature[0], dewpoint[0])

    cape, cin = cape_cin(p, temperature, dewpoint, parcel_prof)

    assert_almost_equal(cape, 58.0368212 * units('joule / kilogram'), 6)

    assert_almost_equal(cin, -89.8073512 * units('joule / kilogram'), 6)

def test_cape_cin_no_el():

    """Tests that CAPE works with no EL."""

    p = np.array([959., 779.2, 751.3, 724.3]) * units.mbar

    temperature = np.array([22.2, 14.6, 12., 9.4]) * units.celsius

    dewpoint = np.array([19., -11.2, -10.8, -10.4]) * units.celsius

    parcel_prof = parcel_profile(p, temperature[0], dewpoint[0]).to('degC')

    cape, cin = cape_cin(p, temperature, dewpoint, parcel_prof)

    w = 0.012

    rh = relative_humidity_from_mixing_ratio(w, temperature, p)

    assert_almost_equal(rh, 81.7219 * units.percent, 3)

def test_mixing_ratio_from_specific_humidity():

    """Tests mixing ratio from specific humidity."""

    q = 0.012

    w = mixing_ratio_from_specific_humidity(q)

    assert_almost_equal(w, 0.01215, 3)

def test_rh_specific_humidity():

    """Tests relative humidity from specific humidity."""

    p = 1013.25 * units.mbar

    assert_almost_equal(vapor_pressure(998. * units.mbar, 0.04963),

                        73.74925 * units.mbar, 5)

def test_lcl():

    """Test LCL calculation."""

    lcl_pressure, lcl_temperature = lcl(1000. * units.mbar, 30. * units.degC, 20. * units.degC)

    assert_almost_equal(lcl_pressure, 864.761 * units.mbar, 2)

    assert_almost_equal(lcl_temperature, 17.676 * units.degC, 2)

def test_lcl_convergence():

    """Test LCL calculation convergence failure."""

    with pytest.raises(RuntimeError):

    wet_bulb_temperature = 18. * units.degC

    psychrometric_rh = relative_humidity_wet_psychrometric(dry_bulb_temperature,

                                                           wet_bulb_temperature, p)

    assert_almost_equal(psychrometric_rh, 82.8747 * units.percent, 3)

def test_wet_psychrometric_rh_kwargs():

    """Test calculation of relative humidity from wet and dry bulb temperatures."""

    p = 1013.25 * units.mbar

    dry_bulb_temperature = 20. * units.degC

    wet_bulb_temperature = 18. * units.degC

    coeff = 6.1e-4 / units.kelvin

    psychrometric_rh = relative_humidity_wet_psychrometric(dry_bulb_temperature,

                                                           wet_bulb_temperature, p,

                                                           psychrometer_coefficient=coeff)