Merge pull request #1282 from dopplershift/more-pint

More pint fixes

examples/sigma_to_pressure_interpolation.py

@@ -33,9 +33,9 @@
 lon = data.variables['lon'][:]
 time = data.variables['time']
 vtimes = num2date(time[:], time.units)
-temperature = data.variables['temperature'][:] * units.celsius
-pres = data.variables['pressure'][:] * units.pascal
-hgt = data.variables['height'][:] * units.meter
+temperature = units.Quantity(data.variables['temperature'][:], 'degC')
+pres = units.Quantity(data.variables['pressure'][:], 'Pa')
+hgt = units.Quantity(data.variables['height'][:], 'meter')
 
 ####################################
 # Array of desired pressure levels

src/metpy/calc/thermo.py

@@ -125,7 +125,7 @@ def potential_temperature(pressure, temperature):
     --------
     >>> from metpy.units import units
     >>> metpy.calc.potential_temperature(800. * units.mbar, 273. * units.kelvin)
-    <Quantity(290.96653180346203, 'kelvin')>
+    <Quantity(290.9665329591884, 'kelvin')>
 
     """
     return temperature / exner_function(pressure)

src/metpy/plots/station_plot.py

@@ -192,6 +192,8 @@ def plot_parameter(self, location, parameter, formatter='.0f', **kwargs):
         plot_barb, plot_symbol, plot_text
 
         """
+        if hasattr(parameter, 'units'):
+            parameter = parameter.magnitude
         text = self._to_string_list(parameter, formatter)
         return self.plot_text(location, text, **kwargs)
 
@@ -353,8 +355,6 @@ def _to_string_list(vals, fmt):
         if not callable(fmt):
             def formatter(s):
                 """Turn a format string into a callable."""
-                if hasattr(s, 'units'):
-                    s = s.item()
                 return format(s, fmt)
         else:
             formatter = fmt

tests/plots/test_skewt.py

@@ -16,7 +16,7 @@
 from metpy.units import units
 
 
-@pytest.mark.mpl_image_compare(tolerance=.02, remove_text=True, style='default')
+@pytest.mark.mpl_image_compare(tolerance=.0202, remove_text=True, style='default')
 def test_skewt_api():
     """Test the SkewT API."""
     with matplotlib.rc_context({'axes.autolimit_mode': 'data'}):
@@ -47,7 +47,7 @@ def test_skewt_api():
     return fig
 
 
-@pytest.mark.mpl_image_compare(tolerance=.027 if matplotlib.__version__ < '3.2' else 34.4,
+@pytest.mark.mpl_image_compare(tolerance=.0272 if matplotlib.__version__ < '3.2' else 34.4,
                                remove_text=True, style='default')
 def test_skewt_api_units():
     """#Test the SkewT API when units are provided."""
@@ -66,6 +66,9 @@ def test_skewt_api_units():
         skew.plot_moist_adiabats()
         skew.plot_mixing_lines()
 
+        # This works around the fact that newer pint versions default to degrees_Celsius
+        skew.ax.set_xlabel('degC')
+
     return fig
 
 

tests/plots/test_station_plot.py

@@ -83,7 +83,7 @@ def test_station_plot_replace():
     return fig
 
 
-@pytest.mark.mpl_image_compare(tolerance=0.00413, savefig_kwargs={'dpi': 300},
+@pytest.mark.mpl_image_compare(tolerance=0, savefig_kwargs={'dpi': 300},
                                remove_text=True)
 def test_stationlayout_api():
     """Test the StationPlot API."""
@@ -92,7 +92,7 @@ def test_stationlayout_api():
     # testing data
     x = np.array([1, 5])
     y = np.array([2, 4])
-    data = {'temp': np.array([32., 212.]) * units.degF, 'u': np.array([2, 0]) * units.knots,
+    data = {'temp': np.array([33., 212.]) * units.degF, 'u': np.array([2, 0]) * units.knots,
             'v': np.array([0, 5]) * units.knots, 'stid': ['KDEN', 'KSHV'], 'cover': [3, 8]}
 
     # Set up the layout
@@ -151,15 +151,15 @@ def test_station_layout_names():
     assert sorted(layout.names()) == ['cover', 'stid', 'temp', 'u', 'v']
 
 
-@pytest.mark.mpl_image_compare(tolerance=0.0072, savefig_kwargs={'dpi': 300}, remove_text=True)
+@pytest.mark.mpl_image_compare(tolerance=0, savefig_kwargs={'dpi': 300}, remove_text=True)
 def test_simple_layout():
     """Test metpy's simple layout for station plots."""
     fig = plt.figure(figsize=(9, 9))
 
     # testing data
     x = np.array([1, 5])
     y = np.array([2, 4])
-    data = {'air_temperature': np.array([32., 212.]) * units.degF,
+    data = {'air_temperature': np.array([33., 212.]) * units.degF,
             'dew_point_temperature': np.array([28., 80.]) * units.degF,
             'air_pressure_at_sea_level': np.array([29.92, 28.00]) * units.inHg,
             'eastward_wind': np.array([2, 0]) * units.knots,