Fix empty response of TemporalAggregate and Cumulative (#18)

CHANGES.rst

@@ -5,7 +5,9 @@ Changelog of dask-geomodeling
 2.1.1 (unreleased)
 ------------------
 
-- Nothing changed yet.
+- Fix empty response of TemporalAggregate and Cumulative.
+
+- Fix elementwise raster blocks in case of empty datasets.
 
 
 2.1.0 (2019-11-15)

dask_geomodeling/raster/elemwise.py

@@ -58,8 +58,9 @@ def get_sources_and_requests(self, **request):
         if start is not None and stop is not None:
             # limit request to self.period so that resulting data is aligned
             period = self.period
-            request["start"] = max(start, period[0])
-            request["stop"] = min(stop, period[1])
+            if period is not None:
+                request["start"] = max(start, period[0])
+                request["stop"] = min(stop, period[1])
 
         process_kwargs = {"dtype": self.dtype.name, "fillvalue": self.fillvalue}
         sources_and_requests = [(source, request) for source in self.args]
@@ -265,6 +266,10 @@ def math_process_func(process_kwargs, *args):
                     nodata_mask = _nodata_mask
                 else:
                     nodata_mask |= _nodata_mask
+            else:
+                raise TypeError(
+                    "Cannot apply math function to value {}".format(data)
+                )
 
         if dtype == np.dtype("bool"):
             no_data_value = None

dask_geomodeling/raster/temporal.py

@@ -509,7 +509,7 @@ def get_sources_and_requests(self, **request):
 
         start, stop = self._snap_to_resampled_labels(start, stop)
         if start is None:
-            return [({"mode": "empty"}, None)]
+            return [({"empty": True, "mode": mode}, None)]
 
         # a time request does not involve a request to self.source
         if mode == "time":
@@ -557,7 +557,7 @@ def get_sources_and_requests(self, **request):
     def process(process_kwargs, time_data=None, data=None):
         mode = process_kwargs["mode"]
         # handle empty data
-        if mode == "empty":
+        if process_kwargs.get("empty"):
             return None if mode == "vals" else {mode: []}
         start = process_kwargs["start"]
         stop = process_kwargs["stop"]
@@ -745,7 +745,7 @@ def get_sources_and_requests(self, **request):
         time_data = self.source.get_data(mode="time", start=start, stop=stop)
         if time_data is None or not time_data.get("time"):
             # return early for an empty source
-            return [({"mode": "empty"}, None)]
+            return [({"empty": True, "mode": mode}, None)]
 
         # get the periods from the first and last timestamp
         start = time_data["time"][0]
@@ -783,7 +783,7 @@ def get_sources_and_requests(self, **request):
     def process(process_kwargs, time_data=None, data=None):
         mode = process_kwargs["mode"]
         # handle empty data
-        if mode == "empty":
+        if process_kwargs.get("empty"):
             return None if mode == "vals" else {mode: []}
         if mode == "time":
             return time_data

dask_geomodeling/tests/test_raster.py

@@ -1107,6 +1107,11 @@ def setUp(self):
             "stop": Datetime(2020, 1, 1),
             **self.request,
         }
+        self.request_empty = {
+            "start": Datetime(1970, 1, 1),
+            "stop": Datetime(1971, 1, 1),
+            **self.request,
+        }
 
     def test_period_day_agg(self):
         self.assertEqual(
@@ -1376,6 +1381,20 @@ def test_int_result_dtype(self):
         result = view.get_data(**self.request_all)
         self.assertEqual(result["values"].dtype, np.int32)
 
+    def test_get_data_empty_vals(self):
+        view = self.klass(self.raster, "D")
+        assert view.get_data(**self.request_empty) is None
+
+    def test_get_data_empty_time(self):
+        view = self.klass(self.raster, "D")
+        self.request_empty["mode"] = "time"
+        assert view.get_data(**self.request_empty) == {"time": []}
+
+    def test_get_data_empty_meta(self):
+        view = self.klass(self.raster, "D")
+        self.request_empty["mode"] = "meta"
+        assert view.get_data(**self.request_empty) == {"meta": []}
+
 
 class TestCumulative(unittest.TestCase):
     klass = raster.Cumulative
@@ -1409,6 +1428,11 @@ def setUp(self):
             "stop": Datetime(2020, 1, 1),
             **self.request,
         }
+        self.request_empty = {
+            "start": Datetime(1970, 1, 1),
+            "stop": Datetime(1971, 1, 1),
+            **self.request,
+        }
 
     def test_get_data_meta(self):
         view = self.klass(self.raster, frequency="W", statistic="sum")
@@ -1493,6 +1517,16 @@ def test_get_data_count(self):
         result = view.get_data(**self.request_all)
         assert_equal(result["values"], [[[1, 1, 0]], [[2, 2, 0]], [[3, 3, 0]]])
 
+    def test_get_data_empty_vals(self):
+        view = self.klass(self.raster, frequency="D", statistic="sum")
+        assert view.get_data(**self.request_empty) is None
+
+
+    def test_get_data_empty_meta(self):
+        view = self.klass(self.raster, frequency="D", statistic="sum")
+        self.request_empty["mode"] = "meta"
+        assert view.get_data(**self.request_empty) == {"meta": []}
+
 
 class TestBase(unittest.TestCase):
     def setUp(self):