PERF: performance regression in frame/apply (GH5654)

Author: jreback

pandas/core/frame.py

@@ -3434,7 +3434,7 @@ def _apply_standard(self, func, axis, ignore_failures=False, reduce=True):
 
                 if self._is_mixed_type:  # maybe a hack for now
                     raise AssertionError('Must be mixed type DataFrame')
-                values = self.values.ravel()
+                values = self.values
                 dummy = Series(NA, index=self._get_axis(axis),
                                dtype=values.dtype)
 

vb_suite/frame_methods.py

@@ -289,3 +289,12 @@ def f(K=100):
 frame_isnull  = Benchmark('isnull(df)', setup,
                            start_date=datetime(2012,1,1))
 
+#----------------------------------------------------------------------
+# apply
+
+setup = common_setup + """
+s = Series(np.arange(1028.))
+df = DataFrame({ i:s for i in range(1028) })
+"""
+frame_apply_user_func = Benchmark('df.apply(lambda x: np.corrcoef(x,s)[0,1])', setup,
+                           start_date=datetime(2012,1,1))