Update groupby.py

Author: Illviljan

asv_bench/benchmarks/groupby.py

@@ -36,10 +36,8 @@ class GroupByDask(GroupBy):
     def setup(self, *args, **kwargs):
         requires_dask()
         super().setup(**kwargs)
-        self.ds1d = self.ds1d.sel(dim_0=slice(self.n * 0.5)).chunk({"dim_0": 50})
-        self.ds2d = self.ds2d.sel(dim_0=slice(self.n * 0.5)).chunk(
-            {"dim_0": 50, "z": 4}
-        )
+        self.ds1d = self.ds1d.sel(dim_0=slice(self.n // 2)).chunk({"dim_0": 50})
+        self.ds2d = self.ds2d.sel(dim_0=slice(self.n // 2)).chunk({"dim_0": 50, "z": 4})
 
 
 class GroupByDataFrame(GroupBy):