Consolidate DayLocator interval checks

LindyBalboa · LindyBalboa · commit b5c9aa416956 · 2016-08-21T12:05:29.000+02:00
diff --git a/lib/matplotlib/dates.py b/lib/matplotlib/dates.py
@@ -1241,12 +1241,8 @@ def __init__(self, bymonthday=None, interval=1, tz=None):
 
         Default is to tick every day of the month: ``bymonthday=range(1,32)``
         """
-        if interval < 1:
-            raise ValueError("The interval parameter must be an integer "
-                             "greater than or equal to one.")
-        if not isinstance(interval, int):
-            raise ValueError("The interval parameter must be an integer "
-                             "greater than or equal to one.")
+        if not interval == int(interval) or interval < 1:
+            raise ValueError("interval must be an integer greater than 0")
         if bymonthday is None:
             bymonthday = range(1, 32)
         elif isinstance(bymonthday, np.ndarray):
