EP-2151 Open-EO#117 Open-EO#125 fix DataCube.ndvi

openeo/rest/datacube.py

@@ -11,7 +11,7 @@
 from openeo.internal.graphbuilder import GraphBuilder
 from openeo.imagecollection import ImageCollection, CollectionMetadata
 from openeo.job import Job
-from openeo.util import get_temporal_extent
+from openeo.util import get_temporal_extent, dict_no_none
 
 if hasattr(typing, 'TYPE_CHECKING') and typing.TYPE_CHECKING:
     # Only import this for type hinting purposes. Runtime import causes circular dependency issues.
@@ -692,19 +692,22 @@ def count_time(self) -> 'ImageCollection':
         """
         return self._reduce_time(reduce_function="count")
 
-    def ndvi(self, name="ndvi") -> 'ImageCollection':
+    def ndvi(self, nir: str = None, red: str = None, target_band: str = None) -> 'ImageCollection':
         """ Normalized Difference Vegetation Index (NDVI)
 
-            :param name: Name of the newly created band
+            :param nir: name of NIR band
+            :param red: name of red band
+            :param target_band: (optional) name of the newly created band
 
             :return: An ImageCollection instance
         """
-        process_id = 'ndvi'
-        args = {
-            'data': {'from_node': self.node_id},
-            'name': name
-        }
-        return self.graph_add_process(process_id, args)
+        return self.graph_add_process(
+            process_id='ndvi',
+            args=dict_no_none(
+                data={'from_node': self.builder.result_node},
+                nir=nir, red=red, target_band=target_band
+            )
+        )
 
     @deprecated("use 'linear_scale_range' instead")
     def stretch_colors(self, min, max) -> 'ImageCollection':

openeo/util.py

@@ -27,6 +27,17 @@ def date_to_rfc3339(d: Any) -> str:
     raise NotImplementedError("TODO")
 
 
+def dict_no_none(**kwargs):
+    """
+    Helper to build a dict containing given key-value pairs where the value is not None.
+    """
+    return {
+        k: v
+        for k, v in kwargs.items()
+        if v is not None
+    }
+
+
 def first_not_none(*args):
     """Return first item from given arguments that is not None."""
     for item in args:

tests/rest/test_datacube.py

@@ -57,6 +57,26 @@ def test_merge_cubes(con100: Connection):
     }
 
 
+def test_ndvi_simple(con100: Connection):
+    ndvi = con100.load_collection("S2").ndvi()
+    assert sorted(ndvi.graph.keys()) == ["loadcollection1", "ndvi1"]
+    assert ndvi.graph["ndvi1"] == {
+        "process_id": "ndvi",
+        "arguments": {"data": {"from_node": "loadcollection1"}},
+        "result": True,
+    }
+
+
+def test_ndvi_args(con100: Connection):
+    ndvi = con100.load_collection("S2").ndvi(nir="nirr", red="rred", target_band="ndvii")
+    assert sorted(ndvi.graph.keys()) == ["loadcollection1", "ndvi1"]
+    assert ndvi.graph["ndvi1"] == {
+        "process_id": "ndvi",
+        "arguments": {"data": {"from_node": "loadcollection1"}, "nir": "nirr", "red": "rred", "target_band": "ndvii"},
+        "result": True,
+    }
+
+
 def test_viewing_service(con100: Connection, requests_mock):
     def check_request(request):
         assert request.json() == {

tests/test_util.py

@@ -6,7 +6,15 @@
 
 import pytest
 
-from openeo.util import first_not_none, get_temporal_extent, TimingLogger, ensure_list, ensure_dir
+from openeo.util import first_not_none, get_temporal_extent, TimingLogger, ensure_list, ensure_dir, dict_no_none
+
+
+def test_dict_no_none():
+    assert dict_no_none() == {}
+    assert dict_no_none(a=3) == {"a": 3}
+    assert dict_no_none(a=3, b=0, c="foo") == {"a": 3, "b": 0, "c": "foo"}
+    assert dict_no_none(a=3, b="", c="foo") == {"a": 3, "b": "", "c": "foo"}
+    assert dict_no_none(a=3, b=None, c="foo") == {"a": 3, "c": "foo"}
 
 
 @pytest.mark.parametrize(['input', 'expected'], [