fix uncertainty division bug and add test

Tony S Yu · Tony S Yu · commit 4e57be7cf903 · 2009-07-22T11:08:36.000-04:00
diff --git a/quantities/tests/test_60_uncertainty.py b/quantities/tests/test_60_uncertainty.py
@@ -81,3 +81,7 @@ def test_uncertainquantity_divide():
         str(a/2),
         '[ 0.5  1. ] m\n±[ 0.05  0.1 ] m (1σ)'
     )
+    assert_equal(
+        str(1/a),
+        '[ 1.   0.5] 1/m\n±[ 0.1   0.05] 1/m (1σ)'
+    )
diff --git a/quantities/uncertainquantity.py b/quantities/uncertainquantity.py
@@ -148,7 +148,7 @@ def __truediv__(self, other):
     def __rtruediv__(self, other):
         temp = UncertainQuantity(
             1/self.magnitude, self.dimensionality**-1,
-            1/self.uncertainty.magnitude, copy=False
+            self.relative_uncertainty/self.magnitude, copy=False
         )
         return other * temp
 

Original file line number	Diff line number	Diff line change
`@@ -81,3 +81,7 @@ def test_uncertainquantity_divide():`
`81`	`81`	`str(a/2),`
`82`	`82`	`'[ 0.5 1. ] m\n±[ 0.05 0.1 ] m (1σ)'`
`83`	`83`	`)`
	`84`	`+ assert_equal(`
	`85`	`+ str(1/a),`
	`86`	`+ '[ 1. 0.5] 1/m\n±[ 0.1 0.05] 1/m (1σ)'`
	`87`	`+ )`
Original file line number	Diff line number	Diff line change
`@@ -148,7 +148,7 @@ def __truediv__(self, other):`
`148`	`148`	`def __rtruediv__(self, other):`
`149`	`149`	`temp = UncertainQuantity(`
`150`	`150`	`1/self.magnitude, self.dimensionality**-1,`
`151`		`- 1/self.uncertainty.magnitude, copy=False`
	`151`	`+ self.relative_uncertainty/self.magnitude, copy=False`
`152`	`152`	`)`
`153`	`153`	`return other * temp`
`154`	`154`