Decrease test_monotonic_inc by one order and change is_monotonic

Author: makbigc

asv_bench/benchmarks/index_object.py

@@ -184,12 +184,13 @@ def time_get_loc(self):
 class IntervalIndexMethod(object):
     # GH 24813
     def setup(self):
-        N = 10000
+        N = 10**5
         left = np.append(np.arange(N), np.array(0))
         right = np.append(np.arange(1, N + 1), np.array(1))
         self.intv = IntervalIndex.from_arrays(left, right)
 
     def time_monotonic_inc(self):
         self.intv.is_monotonic_increasing
 
+
 from .pandas_vb_common import setup  # noqa: F401

pandas/core/indexes/interval.py

@@ -440,7 +440,7 @@ def is_monotonic(self):
         Return True if the IntervalIndex is monotonic increasing (only equal or
         increasing values), else False
         """
-        return self._multiindex.is_monotonic
+        return self.is_monotonic_increasing
 
     @cache_readonly
     def is_monotonic_increasing(self):
@@ -458,8 +458,6 @@ def is_monotonic_increasing(self):
             # we have mixed types and np.lexsort is not happy
             return Index(self.values).is_monotonic
 
-        return self._multiindex.is_monotonic_increasing
-
     @cache_readonly
     def is_monotonic_decreasing(self):
         """