Fix units_scatter.py example, which was broken before this PR.

efiring · anntzer · commit a23a30b0290d · 2018-12-12T12:20:53.000+01:00
Prior to this, examples/units/basic_units.py was not actually
handling masked arrays, and units_scatter.py was not plotting
its third panel correctly.
diff --git a/examples/units/basic_units.py b/examples/units/basic_units.py
@@ -174,7 +174,10 @@ def get_compressed_copy(self, mask):
     def convert_to(self, unit):
         if unit == self.unit or not unit:
             return self
-        new_value = self.unit.convert_value_to(self.value, unit)
+        try:
+            new_value = self.unit.convert_value_to(self.value, unit)
+        except AttributeError:
+            new_value = self
         return TaggedValue(new_value, unit)
 
     def get_value(self):
@@ -345,7 +348,20 @@ def convert(val, unit, axis):
         if units.ConversionInterface.is_numlike(val):
             return val
         if np.iterable(val):
-            return [thisval.convert_to(unit).get_value() for thisval in val]
+            if np.ma.isMaskedArray(val):
+                val = val.astype(float).filled(np.nan)
+            out = np.empty((len(val),),  dtype=float)
+            for i, thisval in enumerate(val):
+                if np.ma.is_masked(thisval):
+                    out[i] = np.nan
+                else:
+                    try:
+                        out[i] = thisval.convert_to(unit).get_value()
+                    except AttributeError:
+                        out[i] = thisval
+            return out
+        if np.ma.is_masked(val):
+            return np.nan
         else:
             return val.convert_to(unit).get_value()
 
diff --git a/examples/units/units_scatter.py b/examples/units/units_scatter.py
@@ -27,9 +27,8 @@
 ax2.scatter(xsecs, xsecs, yunits=hertz)
 ax2.axis([0, 10, 0, 1])
 
-ax3.scatter(xsecs, xsecs, yunits=hertz)
-ax3.yaxis.set_units(minutes)
-ax3.axis([0, 10, 0, 1])
+ax3.scatter(xsecs, xsecs, yunits=minutes)
+ax3.axis([0, 10, 0, 0.2])
 
 fig.tight_layout()
 plt.show()
