remove the mask and add attrs to root

Author: keewis

intermediate/hierarchical_computation.ipynb

@@ -45,17 +45,18 @@
    "source": [
     "ds = xr.tutorial.open_dataset(\"air_temperature\")\n",
     "\n",
-    "ds_daily = (\n",
-    "    ds.resample(time=\"D\").mean(\"time\").assign(mask=lambda ds: ds[\"air\"].isel(time=0) >= 293.15)\n",
-    ")\n",
-    "ds_weekly = (\n",
-    "    ds.resample(time=\"W\").mean(\"time\").assign(mask=lambda ds: ds[\"air\"].isel(time=0) >= 293.15)\n",
-    ")\n",
-    "ds_monthly = (\n",
-    "    ds.resample(time=\"ME\").mean(\"time\").assign(mask=lambda ds: ds[\"air\"].isel(time=0) >= 293.15)\n",
-    ")\n",
+    "ds_daily = ds.resample(time=\"D\").mean(\"time\")\n",
+    "ds_weekly = ds.resample(time=\"W\").mean(\"time\")\n",
+    "ds_monthly = ds.resample(time=\"ME\").mean(\"time\")\n",
     "\n",
-    "tree = xr.DataTree.from_dict({\"daily\": ds_daily, \"weekly\": ds_weekly, \"monthly\": ds_monthly})\n",
+    "tree = xr.DataTree.from_dict(\n",
+    "    {\n",
+    "        \"daily\": ds_daily,\n",
+    "        \"weekly\": ds_weekly,\n",
+    "        \"monthly\": ds_monthly,\n",
+    "        \"\": xr.Dataset(attrs={\"name\": \"NMC reanalysis temporal pyramid\"}),\n",
+    "    }\n",
+    ")\n",
     "tree"
    ]
   },