Added logging of units for metrics

pyproject.toml

@@ -56,6 +56,7 @@ dependencies = [
   "pyyaml (>=6.0.2,<7.0.0)",
   "flatdict (==4.0.0)",
   "pytest (>=9.0.3,<10.0.0)",
+  "unyt (>=3.1.0,<4.0.0)",
 ]
 
 [project.urls]

simvue/run.py

@@ -17,6 +17,8 @@
 import humanfriendly
 import datetime
 import os
+from unyt import unyt_quantity
+from unyt.exceptions import UnitParseError
 
 import pydantic
 import re
@@ -183,6 +185,8 @@ def __init__(
         self._executor = Executor(self)
         self._dispatcher: DispatcherBaseClass | None = None
 
+        self._meta_cache: dict[str, typing.Any] = {}
+
         self._folder: Folder | None = None
         self._term_color: bool = True
         self._grids: dict[str, str] = {}
@@ -1680,6 +1684,12 @@ def log_metrics(
             )
         ```
         """
+
+        # If there are any metric units to be uploaded do so now
+        if _units := self._meta_cache.get("metrics"):
+            self.update_metadata({"simvue": {"metrics": _units}})
+            del self._meta_cache["metrics"]
+
         # TODO: When metrics and grids are combined into a single entity
         # this can be removed. For now need to separate tensor based metrics
         # from regular
@@ -2586,3 +2596,40 @@ def log_alert(
         _alert.commit()
 
         return True
+
+    @prettify_pydantic
+    @pydantic.validate_call
+    def set_metric_units(
+        self,
+        metric_name: MetricKeyString,
+        *,
+        units: str,
+        mks_unit: str | None = None,
+        mks_conversion: float | None = None,
+    ) -> None:
+        """Define units for metrics.
+
+        Parameters
+        ----------
+        metric_name : str
+            name of metric to assign units to
+        units : str
+            unit symbol
+        label : str | None, optional
+            alternative longer name for units
+        """
+        self._meta_cache.setdefault("metrics", {})
+
+        try:
+            _unit_obj = unyt_quantity.from_string(units)
+            self._meta_cache["metrics"][metric_name] = {
+                "units": units,
+                "mks_conversion": mks_conversion or float(_unit_obj.in_mks().value),
+                "mks_units": mks_unit or f"{_unit_obj.in_mks().units}",
+            }
+        except UnitParseError:
+            self._meta_cache["metrics"][metric_name] = {
+                "units": units,
+                "mks_conversion": mks_conversion,
+                "mks_units": mks_unit,
+            }

tests/functional/test_run_class.py

@@ -1724,3 +1724,18 @@ def test_no_alert_dupes_different_run(alert_type: typing.Literal["user", "events
             else:
                 MetricsRangeAlert(identifier=created_id).delete()
 
+
+@pytest.mark.run
+@pytest.mark.online
+def test_set_metric_units(create_plain_run: tuple[sv_run.Run, dict]) -> None:
+    run, _ = create_plain_run
+    run.set_metric_units("x", units="ft")
+    run.set_metric_units("y", units="m")
+    run.set_metric_units("z", units="Foobars", mks_conversion=3.542, mks_unit="m")
+    run.log_metrics({"x": 10, "y": 3, "z": 22})
+
+    _metadata = RunObject(run.id).metadata
+    assert (_metric_data := _metadata.get("simvue", {}).get("metrics"))
+    assert _metric_data["x"] == {"units": "ft", "mks_units": "m", "mks_conversion": 0.3048}
+    assert _metric_data["y"] == {"units": "m", "mks_units": "m", "mks_conversion": 1}
+    assert _metric_data["z"] == {"units": "Foobars", "mks_units": "m", "mks_conversion": 3.542}