fix: Make rochester_lookup compatible with dask_awkward

src/coffea/lookup_tools/rochester_lookup.py

@@ -1,4 +1,5 @@
 import awkward
+import dask_awkward as dak
 import numpy
 
 from coffea.lookup_tools.dense_lookup import dense_lookup
@@ -75,7 +76,7 @@ def _error(self, func, *args):
 
         newargs = args + (0, 0)
         default = func(*newargs)
-        result = numpy.zeros_like(default)
+        result = awkward.zeros_like(default)
         for s in range(self._nsets):
             oneOver = 1.0 / self._members[s]
             for m in range(self._members[s]):
@@ -226,12 +227,27 @@ def _kExtra(self, kpt, eta, nl, u, s=0, m=0):
         cbN_flat = awkward.flatten(cbN)
         cbS_flat = awkward.flatten(cbS)
 
-        invcdf = awkward.unflatten(
-            doublecrystalball.ppf(
-                u_flat, cbA_flat, cbA_flat, cbN_flat, cbN_flat, loc, cbS_flat
-            ),
-            counts,
-        )
+        args = (u_flat, cbA_flat, cbA_flat, cbN_flat, cbN_flat, loc, cbS_flat)
+
+        if any(isinstance(arg, dak.Array) for arg in args):
+
+            def apply(*args):
+                args_lz = [
+                    awkward.typetracer.length_zero_if_typetracer(arg) for arg in args
+                ]
+                out = awkward.Array(doublecrystalball.ppf(*args_lz))
+                if awkward.backend(args[0]) == "typetracer":
+                    out = awkward.Array(
+                        out.layout.to_typetracer(forget_length=True),
+                        behavior=out.behavior,
+                    )
+                return out
+
+            invcdf = dak.map_partitions(apply, *args)
+        else:
+            invcdf = doublecrystalball.ppf(*args)
+
+        invcdf = awkward.unflatten(invcdf, counts)
 
         x = awkward.where(
             mask,

tests/test_lookup_tools.py

@@ -372,8 +372,6 @@ def test_jec_txt_effareas():
 
 
 def test_rochester():
-    pytest.xfail("weird side effect from running other tests... passes by itself")
-
     rochester_data = lookup_tools.txt_converters.convert_rochester_file(
         "tests/samples/RoccoR2018.txt.gz", loaduncs=True
     )
@@ -390,27 +388,29 @@ def test_rochester():
 
     # test against nanoaod
     events = NanoEventsFactory.from_root(
-        os.path.abspath("tests/samples/nano_dimuon.root")
+        {os.path.abspath("tests/samples/nano_dimuon.root"): "Events"},
+        permit_dask=True,
     ).events()
 
     data_k = rochester.kScaleDT(
         events.Muon.charge, events.Muon.pt, events.Muon.eta, events.Muon.phi
     )
-    data_k = np.array(ak.flatten(data_k))
+    data_k = ak.flatten(data_k).compute().to_numpy()
     assert all(np.isclose(data_k, official_data_k))
     data_err = rochester.kScaleDTerror(
         events.Muon.charge, events.Muon.pt, events.Muon.eta, events.Muon.phi
     )
-    data_err = np.array(ak.flatten(data_err), dtype=float)
+    data_err = ak.flatten(data_err).compute().to_numpy()
     assert all(np.isclose(data_err, official_data_err, atol=1e-8))
 
     # test against mc
     events = NanoEventsFactory.from_root(
-        os.path.abspath("tests/samples/nano_dy.root")
+        {os.path.abspath("tests/samples/nano_dy.root"): "Events"},
+        permit_dask=True,
     ).events()
 
     hasgen = ~np.isnan(ak.fill_none(events.Muon.matched_gen.pt, np.nan))
-    mc_rand = ak.unflatten(mc_rand, ak.num(hasgen))
+    mc_rand = ak.unflatten(dak.from_awkward(ak.Array(mc_rand), 1), ak.num(hasgen))
     mc_kspread = rochester.kSpreadMC(
         events.Muon.charge[hasgen],
         events.Muon.pt[hasgen],
@@ -426,10 +426,10 @@ def test_rochester():
         events.Muon.nTrackerLayers[~hasgen],
         mc_rand[~hasgen],
     )
-    mc_k = np.array(ak.flatten(ak.ones_like(events.Muon.pt)))
-    hasgen_flat = np.array(ak.flatten(hasgen))
-    mc_k[hasgen_flat] = np.array(ak.flatten(mc_kspread))
-    mc_k[~hasgen_flat] = np.array(ak.flatten(mc_ksmear))
+    mc_k = ak.flatten(ak.ones_like(events.Muon.pt)).compute().to_numpy()
+    hasgen_flat = ak.flatten(hasgen).compute().to_numpy()
+    mc_k[hasgen_flat] = ak.flatten(mc_kspread).compute().to_numpy()
+    mc_k[~hasgen_flat] = ak.flatten(mc_ksmear).compute().to_numpy()
     assert all(np.isclose(mc_k, official_mc_k))
 
     mc_errspread = rochester.kSpreadMCerror(
@@ -447,9 +447,9 @@ def test_rochester():
         events.Muon.nTrackerLayers[~hasgen],
         mc_rand[~hasgen],
     )
-    mc_err = np.array(ak.flatten(ak.ones_like(events.Muon.pt)))
-    mc_err[hasgen_flat] = np.array(ak.flatten(mc_errspread))
-    mc_err[~hasgen_flat] = np.array(ak.flatten(mc_errsmear))
+    mc_err = ak.flatten(ak.ones_like(events.Muon.pt)).compute().to_numpy()
+    mc_err[hasgen_flat] = ak.flatten(mc_errspread).compute().to_numpy()
+    mc_err[~hasgen_flat] = ak.flatten(mc_errsmear).compute().to_numpy()
     assert all(np.isclose(mc_err, official_mc_err, atol=1e-8))