Unidata / MetPy

    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)

    assert_almost_equal(cape, 0.08750805 * units('joule / kilogram'), 6)

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

def test_cape_cin_no_lfc():

    """Tests that CAPE is zero with no LFC."""

    p = np.array([959., 779.2, 751.3, 724.3, 700., 269.]) * units.mbar

    temperature = np.array([22.2, 24.6, 22., 20.4, 18., -10.]) * 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]).to('degC')

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

    assert_almost_equal(cape, 0.0 * units('joule / kilogram'), 6)

def test_rh_specific_humidity():

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

    p = 1013.25 * units.mbar

    temperature = 20. * units.degC

    q = 0.012

    rh = relative_humidity_from_specific_humidity(q, temperature, p)

    assert_almost_equal(rh, 82.7145 * units.percent, 3)

def test_cape_cin():

    """Tests the basic CAPE and CIN calculation."""

    p = np.array([959., 779.2, 751.3, 724.3, 700., 269.]) * units.mbar

    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])

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

    with pytest.raises(RuntimeError):

        lcl(1000. * units.mbar, 30. * units.degC, 20. * units.degC, max_iters=2)

def test_lfc_basic():

    """Test LFC calculation."""

    levels = np.array([959., 779.2, 751.3, 724.3, 700., 269.]) * units.mbar

    temperatures = np.array([22.2, 14.6, 12., 9.4, 7., -49.]) * units.celsius

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

    l = lfc(levels, temperatures, dewpoints)

    assert_almost_equal(l[0], 727.468 * units.mbar, 2)

    assert_almost_equal(l[1], 9.705 * units.celsius, 2)

    psychrometric_rh = relative_humidity_wet_psychrometric(dry_bulb_temperature,

                                                           wet_bulb_temperature, p,

                                                           psychrometer_coefficient=coeff)

    assert_almost_equal(psychrometric_rh, 82.9701 * units.percent, 3)

def test_rh_mixing_ratio():

    """Tests relative humidity from mixing ratio."""

    p = 1013.25 * units.mbar

    temperature = 20. * units.degC

    w = 0.012

    rh = relative_humidity_from_mixing_ratio(w, temperature, p)

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