Add warning to default enhancement

satpy/enhancements/contrast.py

@@ -20,6 +20,7 @@
 
 import logging
 import typing
+import warnings
 from collections import namedtuple
 from numbers import Number
 from typing import Optional
@@ -38,6 +39,31 @@
 LOG = logging.getLogger(__name__)
 
 
+def warn_if_float_debug_otherwise(img, msg=""):
+    """Perform no enhancement but emit a warning if data is floating point.
+
+    The warning message is specified by the ``msg`` keyword argument
+    and can be a format string. Keyword arguments for the message
+    formatting are taken from the underlying ``DataArray``s ``.attrs``
+    dictionary.
+
+    """
+    formatted_msg = msg.format(**img.data.attrs)
+    if np.issubdtype(img.data.dtype, np.floating):
+        warnings.warn(formatted_msg, UserWarning, stacklevel=2)
+    else:
+        LOG.debug(formatted_msg)
+    return img
+
+
+def stretch_if_floating(img, **kwargs):
+    """Perform a regular linear stretch but warn about no other enhancement."""
+    # if np.issubdtype(img.data.dtype, np.floating):
+    #     return stretch(img, **kwargs)
+    # return img
+    return stretch(img, **kwargs)
+
+
 def stretch(img, **kwargs):
     """Perform stretch."""
     return img.stretch(**kwargs)

satpy/etc/enhancements/generic.yaml

@@ -3,9 +3,15 @@
 enhancements:
   default:
     operations:
-    - name: stretch
-      method: !!python/name:satpy.enhancements.contrast.stretch
-      kwargs: {stretch: linear}
+      - name: warn_no_predefined
+        method: !!python/name:satpy.enhancements.contrast.warn_if_float_debug_otherwise
+        kwargs:
+          # Satpy 1.0+
+          # msg: "No YAML enhancement found for {name!r}. Falling back to a dynamic linear stretch in case of floating point data, or no enhancement otherwise. See https://satpy.readthedocs.io/en/stable/enhancements.html for documentation on defining an enhancement."
+          msg: "No YAML enhancement found for {name!r}. Falling back to a dynamic linear stretch in case. In Satpy 1.0, non-floating data will no longer be scaled by this enhancement (ex. integer category products). See https://satpy.readthedocs.io/en/stable/enhancements.html for documentation on defining an enhancement."
+      - name: stretch
+        method: !!python/name:satpy.enhancements.contrast.stretch_if_floating
+        kwargs: {stretch: linear}
   reflectance_default:
     standard_name: toa_bidirectional_reflectance
     operations:

satpy/tests/compositor_tests/test_fill.py

@@ -46,15 +46,15 @@ def setUp(self):
         a[:, 1, 0] = 0.3
         a[:, 1, 1] = 0.4
         a = da.from_array(a, a.shape)
-        self.data_a = xr.DataArray(a, attrs={"test": "a", "start_time": start_time},
+        self.data_a = xr.DataArray(a, attrs={"test": "a", "start_time": start_time, "name": "a"},
                                    coords={"bands": bands}, dims=("bands", "y", "x"))
         b = np.zeros((3, 2, 2), dtype=np.float32)
         b[:, 0, 0] = np.nan
         b[:, 0, 1] = 0.25
         b[:, 1, 0] = 0.50
         b[:, 1, 1] = 0.75
         b = da.from_array(b, b.shape)
-        self.data_b = xr.DataArray(b, attrs={"test": "b", "start_time": start_time},
+        self.data_b = xr.DataArray(b, attrs={"test": "b", "start_time": start_time, "name": "b"},
                                    coords={"bands": bands}, dims=("bands", "y", "x"))
 
         sza = np.array([[80., 86.], [94., 100.]], dtype=np.float32)

satpy/tests/compositor_tests/test_resolution.py

@@ -225,6 +225,7 @@ def test_compositor(self):
         # Three shades of grey
         rgb_arr = np.array([1, 50, 100, 200, 1, 50, 100, 200, 1, 50, 100, 200])
         rgb = xr.DataArray(rgb_arr.reshape((3, 2, 2)),
+                           attrs={"name": "rgb"},
                            dims=["bands", "y", "x"], coords={"bands": ["R", "G", "B"]})
         # 100 % luminance -> all result values ~1.0
         lum = xr.DataArray(np.array([[100., 100.], [100., 100.]]),

satpy/tests/enhancement_tests/test_enhancer.py

@@ -282,7 +282,7 @@ def test_enhance_empty_config(self, test_configs_path):
 
         from satpy.enhancements.enhancer import Enhancer, get_enhanced_image
         ds = DataArray(np.arange(1, 11.).reshape((2, 5)),
-                       attrs=dict(sensor="test_empty", mode="L"),
+                       attrs=dict(sensor="test_empty", mode="L", name="1"),
                        dims=["y", "x"])
         e = Enhancer()
         assert e.enhancement_tree is not None
@@ -296,7 +296,7 @@ def test_enhance_with_sensor_no_entry(self, test_configs_path):
 
         from satpy.enhancements.enhancer import Enhancer, get_enhanced_image
         ds = DataArray(np.arange(1, 11.).reshape((2, 5)),
-                       attrs=dict(sensor="test_sensor2", mode="L"),
+                       attrs=dict(sensor="test_sensor2", mode="L", name="1"),
                        dims=["y", "x"])
         e = Enhancer()
         assert e.enhancement_tree is not None

satpy/tests/enhancement_tests/test_stretching.py

@@ -21,61 +21,72 @@
 from .utils import create_ch1, create_ch2, create_rgb, run_and_check_enhancement, run_and_check_enhancement_with_dtype
 
 
-class TestEnhancementsStretching:
-    """Class for testing enhancements in satpy.enhancements.contrast module."""
-
-    def setup_method(self):
-        """Create test data used by every test."""
-        self.ch1 = create_ch1()
-        self.ch2 = create_ch2()
-        self.rgb = create_rgb()
-
-    @pytest.mark.parametrize("dtype", [np.float32, np.float64])
-    def test_cira_stretch(self, dtype):
-        """Test applying the cira_stretch."""
-        from satpy.enhancements.contrast import cira_stretch
-
-        expected = np.array([[
-            [np.nan, -7.04045974, -7.04045974, 0.79630132, 0.95947296],
-            [1.05181359, 1.11651012, 1.16635571, 1.20691137, 1.24110186]]], dtype=dtype)
-        run_and_check_enhancement_with_dtype(cira_stretch, self.ch1.astype(dtype), expected)
-
-    def test_reinhard(self):
-        """Test the reinhard algorithm."""
-        from satpy.enhancements.contrast import reinhard_to_srgb
-        expected = np.array([[[np.nan, 0., 0., 0.93333793, 1.29432402],
-                              [1.55428709, 1.76572249, 1.94738635, 2.10848544, 2.25432809]],
-
-                             [[np.nan, 0., 0., 0.93333793, 1.29432402],
-                              [1.55428709, 1.76572249, 1.94738635, 2.10848544, 2.25432809]],
-
-                             [[np.nan, 0., 0., 0.93333793, 1.29432402],
-                              [1.55428709, 1.76572249, 1.94738635, 2.10848544, 2.25432809]]])
-        run_and_check_enhancement(reinhard_to_srgb, self.rgb, expected)
-
-    def test_piecewise_linear_stretch(self):
-        """Test the piecewise_linear_stretch enhancement function."""
-        from satpy.enhancements.contrast import piecewise_linear_stretch
-        expected = np.array([[
-            [np.nan, 0., 0., 0.44378, 0.631734],
-            [0.737562, 0.825041, 0.912521, 1., 1.]]])
-        run_and_check_enhancement(piecewise_linear_stretch,
-                                  self.ch2 / 100.0,
-                                  expected,
-                                  xp=[0., 25., 55., 100., 255.],
-                                  fp=[0., 90., 140., 175., 255.],
-                                  reference_scale_factor=255,
-                                  )
-
-    def test_btemp_threshold(self):
-        """Test applying the cira_stretch."""
-        from satpy.enhancements.contrast import btemp_threshold
-
-        expected = np.array([[
-            [np.nan, 0.946207, 0.892695, 0.839184, 0.785672],
-            [0.73216, 0.595869, 0.158745, -0.278379, -0.715503]]])
-        run_and_check_enhancement(btemp_threshold, self.ch1, expected,
-                                  min_in=-200, max_in=500, threshold=350)
-
-    def tearDown(self):
-        """Clean up."""
+def test_default_enhancement_warning():
+    """Test that the default enhancement warns for floating point data."""
+    from trollimage.xrimage import XRImage
+
+    from satpy.enhancements.contrast import warn_if_float_debug_otherwise
+
+    ch1 = create_ch1()
+    ch1.attrs["name"] = "NAME"
+    img = XRImage(ch1)
+
+    with pytest.warns(UserWarning, match="TEST NAME"):
+        warn_if_float_debug_otherwise(img, msg="TEST {name}")
+
+
+@pytest.mark.parametrize("dtype", [np.float32, np.float64])
+def test_cira_stretch(dtype):
+    """Test applying the cira_stretch."""
+    from satpy.enhancements.contrast import cira_stretch
+
+    ch1 = create_ch1()
+    expected = np.array([[
+        [np.nan, -7.04045974, -7.04045974, 0.79630132, 0.95947296],
+        [1.05181359, 1.11651012, 1.16635571, 1.20691137, 1.24110186]]], dtype=dtype)
+    run_and_check_enhancement_with_dtype(cira_stretch, ch1.astype(dtype), expected)
+
+
+def test_reinhard():
+    """Test the reinhard algorithm."""
+    from satpy.enhancements.contrast import reinhard_to_srgb
+
+    rgb = create_rgb()
+    expected = np.array([[[np.nan, 0., 0., 0.93333793, 1.29432402],
+                          [1.55428709, 1.76572249, 1.94738635, 2.10848544, 2.25432809]],
+
+                         [[np.nan, 0., 0., 0.93333793, 1.29432402],
+                          [1.55428709, 1.76572249, 1.94738635, 2.10848544, 2.25432809]],
+
+                         [[np.nan, 0., 0., 0.93333793, 1.29432402],
+                          [1.55428709, 1.76572249, 1.94738635, 2.10848544, 2.25432809]]])
+    run_and_check_enhancement(reinhard_to_srgb, rgb, expected)
+
+
+def test_piecewise_linear_stretch():
+    """Test the piecewise_linear_stretch enhancement function."""
+    from satpy.enhancements.contrast import piecewise_linear_stretch
+
+    ch2 = create_ch2()
+    expected = np.array([[
+        [np.nan, 0., 0., 0.44378, 0.631734],
+        [0.737562, 0.825041, 0.912521, 1., 1.]]])
+    run_and_check_enhancement(piecewise_linear_stretch,
+                              ch2 / 100.0,
+                              expected,
+                              xp=[0., 25., 55., 100., 255.],
+                              fp=[0., 90., 140., 175., 255.],
+                              reference_scale_factor=255,
+                              )
+
+
+def test_btemp_threshold():
+    """Test applying the cira_stretch."""
+    from satpy.enhancements.contrast import btemp_threshold
+
+    ch1 = create_ch1()
+    expected = np.array([[
+        [np.nan, 0.946207, 0.892695, 0.839184, 0.785672],
+        [0.73216, 0.595869, 0.158745, -0.278379, -0.715503]]])
+    run_and_check_enhancement(btemp_threshold, ch1, expected,
+                              min_in=-200, max_in=500, threshold=350)

satpy/tests/writer_tests/test_core/test_compute.py

@@ -46,7 +46,9 @@ def test_group_results_by_output_file(tmp_path):
     fake_area = create_area_def("sargasso", 4326, resolution=1, width=x, height=x, center=(0, 0))
     fake_scene = make_fake_scene(
         {
-            "dragon_top_height": (dat := xr.DataArray(dims=("y", "x"), data=da.arange(x * x).reshape((x, x)))),
+            "dragon_top_height": (dat := xr.DataArray(
+                dims=("y", "x"),
+                data=da.arange(float(x * x)).reshape((x, x)))),
             "penguin_bottom_height": dat,
             "kraken_depth": dat,
         },