Fix detectorwindow (#507)

scopesim/effects/detector_list.py

@@ -198,24 +198,28 @@ def image_plane_header(self):
         # FIXME: Heavy property.....
         tbl = self.active_table
         pixel_size = np.min(quantity_from_table("pixel_size", tbl, u.mm))
-        x_unit = unit_from_table("x_size", tbl, u.mm)
-        y_unit = unit_from_table("y_size", tbl, u.mm)
-
-        xcen = tbl["x_cen"].data.astype(float)
-        ycen = tbl["y_cen"].data.astype(float)
-        dx = 0.5 * tbl["x_size"].data.astype(float)
-        dy = 0.5 * tbl["y_size"].data.astype(float)
-
-        scale_unit = 1        # either unitless to retain
-        if "pix" in x_unit.name:
-            scale_unit = u.mm / u.pix
-            dx *= pixel_size.value
-            dy *= pixel_size.value
-
-        x_det_min = np.min(xcen - dx) * x_unit * scale_unit
-        x_det_max = np.max(xcen + dx) * x_unit * scale_unit
-        y_det_min = np.min(ycen - dy) * y_unit * scale_unit
-        y_det_max = np.max(ycen + dy) * y_unit * scale_unit
+        x_size_unit = unit_from_table("x_size", tbl, u.mm)
+        y_size_unit = unit_from_table("y_size", tbl, u.mm)
+        # This is mm everywhere in the IRDB, but could be something else...
+        x_cen_unit = unit_from_table("x_cen", tbl, u.mm)
+        y_cen_unit = unit_from_table("y_cen", tbl, u.mm)
+
+        xcen = tbl["x_cen"].data.astype(float) * x_cen_unit
+        ycen = tbl["y_cen"].data.astype(float) * y_cen_unit
+        dx = 0.5 * tbl["x_size"].data.astype(float) * x_size_unit
+        dy = 0.5 * tbl["y_size"].data.astype(float) * y_size_unit
+
+        pixel_scale = u.pixel_scale(pixel_size / u.pixel)
+        with u.set_enabled_equivalencies(pixel_scale):
+            xcen <<= u.mm
+            ycen <<= u.mm
+            dx <<= u.mm
+            dy <<= u.mm
+
+        x_det_min = np.min(xcen - dx)
+        x_det_max = np.max(xcen + dx)
+        y_det_min = np.min(ycen - dy)
+        y_det_max = np.max(ycen + dy)
 
         x_det = [x_det_min.to(u.mm).value, x_det_max.to(u.mm).value]
         y_det = [y_det_min.to(u.mm).value, y_det_max.to(u.mm).value]

scopesim/tests/tests_effects/test_DetectorList.py

@@ -96,7 +96,7 @@ def test_happy_using_x_size_unit_in_mm(self):
             "id": [0, 1],
             "x_cen": [-0.2, 0.2],     # mm
             "y_cen": [0, 0],
-            "x_size": [0.32, 0.32],   # pixel
+            "x_size": [0.32, 0.32],   # mm
             "y_size": [0.32, 0.32],
             "pixsize": [0.01, 0.01],  # mm/pixel
             "angle": [0, 0],
@@ -132,13 +132,12 @@ def test_happy_using_x_size_unit_in_pixels(self):
             assert hdr["NAXIS1"] == 32
             assert hdr["NAXIS2"] == 32
 
-    # FIXME: why is this defined twice???
-    def test_happy_using_x_size_unit_in_pixels(self):
+    def test_happy_using_x_size_unit_in_mm(self):
         det_list = DetectorList(array_dict={
             "id": [0, 1],
             "x_cen": [-0.2, 0.2],     # mm
             "y_cen": [0, 0],
-            "x_size": [0.32, 0.32],   # pixel
+            "x_size": [0.32, 0.32],   # mm
             "y_size": [0.32, 0.32],
             "pixsize": [0.01, 0.01],  # mm/pixel
             "angle": [0, 0],