Backport PR #11532: Fix the display of negative radian values in basic_units.py

dstansby · MeeseeksDev[bot] · commit 40311a35694d · 2018-06-29T09:18:17.000Z
diff --git a/examples/units/basic_units.py b/examples/units/basic_units.py
@@ -298,13 +298,21 @@ def __call__(self, operation, units):
 
 # radians formatting
 def rad_fn(x, pos=None):
-    n = int((x / np.pi) * 2.0 + 0.25)
+    if x >= 0:
+        n = int((x / np.pi) * 2.0 + 0.25)
+    else:
+        n = int((x / np.pi) * 2.0 - 0.25)
+        
     if n == 0:
         return '0'
     elif n == 1:
         return r'$\pi/2$'
     elif n == 2:
         return r'$\pi$'
+    elif n == -1:
+        return r'$-\pi/2$'
+    elif n == -2:
+        return r'$-\pi$'
     elif n % 2 == 0:
         return r'$%s\pi$' % (n//2,)
     else:
