Is time essential

modelskill/comparison/_comparison.py

@@ -50,12 +50,12 @@ def _parse_dataset(data) -> xr.Dataset:
 
     # Validate time
     # assert len(data.dims) == 1, "Only 0-dimensional data are supported"
-    assert "time" in data.dims, "data must have a time dimension"
-    assert isinstance(data.time.to_index(), pd.DatetimeIndex), "time must be datetime"
-    data["time"] = pd.DatetimeIndex(data.time.to_index()).round(freq="100us")  # 0.0001s
-    assert (
-        data.time.to_index().is_monotonic_increasing
-    ), "time must be increasing (please check for duplicate times))"
+    # assert "time" in data.dims, "data must have a time dimension"
+    # assert isinstance(data.time.to_index(), pd.DatetimeIndex), "time must be datetime"
+    # data["time"] = pd.DatetimeIndex(data.time.to_index()).round(freq="100us")  # 0.0001s
+    # assert (
+    #    data.time.to_index().is_monotonic_increasing
+    # ), "time must be increasing (please check for duplicate times))"
 
     # no missing values allowed in Observation
     if data["Observation"].isnull().any():

tests/test_compare.py

@@ -235,6 +235,30 @@ def test_matched_data_quantity():
     assert cmp.quantity == quantity
 
 
+def test_matched_data_not_time_index():
+    df = pd.DataFrame(
+        {
+            "ts_1": [
+                1.0,
+                2.0,
+            ],
+            "sensor_a": [2.0, 3.0],
+        },
+        index=["A", "B"],  # arbitrary index, not time
+    )
+
+    cmp = ms.from_matched(df, obs_item="sensor_a")
+
+    # scatter plot doesn't care about time
+    cmp.plot.scatter()
+
+    # skill metrics do not care about time
+    s = cmp.skill(metrics="mae")
+    assert s.loc["sensor_a", "mae"] == pytest.approx(1.0)
+
+    cmp.plot.timeseries()
+
+
 def test_matched_data_name_xyz():
     df = pd.DataFrame(
         {"ts_1": [1.1, 2.0, 3.0, 4.0], "sensor_a": [0.9, 2.0, 3.0, 4.1]},