add initial tests for stats (LLNL#43)

* Adding unit tests for std.py and percentiles.py

* Adding unit tests for mean, median, minimum and maximum

* Adding unit tests for boxplot, correlation, check normality, and variance

* Add tests for columnar-joined thicket, add a stats fixture to conftest.py

* black formatting
---------

Co-authored-by: Treece Alexander Burgess <[email protected]>
Co-authored-by: Michael Richard McKinsey <[email protected]>

thicket/tests/conftest.py

@@ -51,6 +51,35 @@ def columnar_join_thicket(mpi_scaling_cali, rajaperf_basecuda_xl_cali):
     return thicket_list, thicket_list_cp, combined_th
 
 
+@pytest.fixture
+def stats_columnar_join_thicket(rajaperf_basecuda_xl_cali):
+    """Generator for 'columnar_join' thicket for test_stats.py.
+
+    Arguments:
+        mpi_scaling_cali (list): List of Caliper files for MPI scaling study.
+        rajaperf_basecuda_xl_cali (list): List of Caliper files for base cuda variant.
+
+    Returns:
+        list: List of original thickets, list of deepcopies of original thickets, and
+            columnar-joined thicket.
+    """
+    th_cuda128_1 = Thicket.from_caliperreader(rajaperf_basecuda_xl_cali[0:4])
+    th_cuda128_2 = Thicket.from_caliperreader(rajaperf_basecuda_xl_cali[5:9])
+
+    # To check later if modifications were unexpectedly made
+    th_cuda128_1_deep = th_cuda128_1.deepcopy()
+    th_cuda128_2_deep = th_cuda128_2.deepcopy()
+    thicket_list = [th_cuda128_1, th_cuda128_2]
+    thicket_list_cp = [th_cuda128_1_deep, th_cuda128_2_deep]
+
+    combined_th = Thicket.columnar_join(
+        thicket_list=thicket_list,
+        header_list=["Cuda 1", "Cuda 2"],
+    )
+
+    return thicket_list, thicket_list_cp, combined_th
+
+
 @pytest.fixture
 def data_dir():
     """Return path to the top-level data directory for tests."""