Merge pull request #290 from roman-corgi/crop_bugfix

Bug Fix: Crop Function Checks for Correct Header Keyword

corgidrp/l3_to_l4.py

@@ -37,7 +37,7 @@ def find_star(input_dataset):
 
     return input_dataset.copy()
 
-def crop(input_dataset,sizexy=60,centerxy=None):
+def crop(input_dataset,sizexy=None,centerxy=None):
     """
     
     Crop the Images in a Dataset to a desired field of view. Default behavior is to 
@@ -52,7 +52,8 @@ def crop(input_dataset,sizexy=60,centerxy=None):
     Args:
         input_dataset (corgidrp.data.Dataset): a dataset of Images (any level)
         sizexy (int or array of int): desired frame size, if only one number is provided the 
-            desired shape is assumed to be square, otherwise xy order. Defaults to 60.
+            desired shape is assumed to be square, otherwise xy order. If not provided, 
+            defaults to 60 for NFOV (narrow field-of-view) observations. Defaults to None.
         centerxy (float or array of float): desired center (xy order), should be a pixel intersection (a.k.a 
             half-integer) otherwise the function rounds to the nearest intersection. Defaults to the 
             "STARLOCX/Y" header values.
@@ -65,7 +66,7 @@ def crop(input_dataset,sizexy=60,centerxy=None):
     dataset = input_dataset.copy()
 
     # Require even data shape
-    if not np.all(np.array(sizexy)%2==0):
+    if not sizexy is None and not np.all(np.array(sizexy)%2==0):
         raise UserWarning('Even sizexy is required.')
 
     # Need to loop over frames and reinit dataset because array sizes change
@@ -77,9 +78,12 @@ def crop(input_dataset,sizexy=60,centerxy=None):
         dqhdr = frame.dq_hdr
         errhdr = frame.err_hdr
 
-        # Require that mode is HLC for now
-        if not prihdr['MODE'] == 'HLC':
-            raise UserWarning('Crop function is currently only configured for mode HLC.')
+        # Pick default crop size based on the size of the effective field of view (determined by the Lyot stop)
+        if sizexy is None:
+            if prihdr['LSAMNAME'] == 'NFOV':
+                sizexy = 60
+            else:
+                raise UserWarning('Crop function is currently only configured for NFOV (narrow field-of-view) observations if sizexy is not provided.')
 
         # Assign new array sizes and center location
         frame_shape = frame.data.shape

tests/test_crop.py

@@ -28,9 +28,7 @@ def make_test_dataset(shape=[100,100],centxy=None):
     exthdr['STARLOCY'] = cent[0]
     exthdr['MASKLOCX'] = cent[1]
     exthdr['MASKLOCY'] = cent[0]
-    exthdr['CRPIX1'] = cent[1] + 1
-    exthdr['CRPIX2'] = cent[0] + 1
-    prihdr['MODE'] = 'HLC'
+    prihdr['LSAMNAME'] = 'NFOV'
 
     if len(shape) == 2:
         test_arr[int(cent[0]-0.5):int(cent[0]+1.5),int(cent[1]-0.5):int(cent[1]+1.5)] = 1
@@ -82,7 +80,7 @@ def test_2d_square_offcenter_crop():
         raise Exception("Unexpected result for 2D square offcenter crop test.")
 
 def test_2d_rect_offcenter_crop():
-    """ Test cropping off-center non-square data.
+    """ Tests cropping off-center non-square data.
     """
     test_dataset = make_test_dataset(shape=[100,40],centxy=[24.5,49.5])
     cropped_test_dataset = crop(test_dataset,sizexy=[20,10],centerxy=None)
@@ -91,7 +89,7 @@ def test_2d_rect_offcenter_crop():
         raise Exception("Unexpected result for 2D rect offcenter crop test.")
 
 def test_3d_rect_offcenter_crop():
-    """ Test cropping 3D off-center non-square data.
+    """ Tests cropping 3D off-center non-square data.
     """
     test_dataset = make_test_dataset(shape=[3,100,40],centxy=[24.5,49.5])
     cropped_test_dataset = crop(test_dataset,sizexy=[20,10],centerxy=None)
@@ -101,18 +99,18 @@ def test_3d_rect_offcenter_crop():
     if not cropped_test_dataset[0].data == pytest.approx(goal_rect_arr3d):
         raise Exception("Unexpected result for 2D rect offcenter crop test.")
 
-
-def test_edge_of_FOV():
-    """ Test cropping right at the edge of the data array.
+def test_edge_of_detector():
+    """ Tests that trying to crop a region right at the edge of the 
+    detector succeeds.
     """
     test_dataset = make_test_dataset(shape=[100,100],centxy=[94.5,94.5])
     cropped_test_dataset = crop(test_dataset,sizexy=10,centerxy=None)
 
     if not cropped_test_dataset[0].data == pytest.approx(goal_arr):
         raise Exception("Unexpected result for edge of FOV crop test.")
 
-def test_outside_FOV():
-    """ Test cropping over the edge of the data array.
+def test_outside_detector_edge():
+    """ Tests that trying to crop a region outside the detector fails.
     """
 
     test_dataset = make_test_dataset(shape=[100,100],centxy=[95.5,95.5])
@@ -121,7 +119,8 @@ def test_outside_FOV():
         _ = crop(test_dataset,sizexy=10,centerxy=None)
 
 def test_nonhalfinteger_centxy():
-    """ Test trying to center the crop not on a pixel intersection.
+    """ Tests that trying to crop data to a center that is not at the intersection 
+    of 4 pixels results in centering on the nearest pixel intersection.
     """
     test_dataset = make_test_dataset(shape=[100,100],centxy=[49.5,49.5])
     cropped_test_dataset = crop(test_dataset,sizexy=10,centerxy=[49.7,49.7])
@@ -130,7 +129,8 @@ def test_nonhalfinteger_centxy():
         raise Exception("Unexpected result for non half-integer crop test.")
 
 def test_header_updates_2d():
-    """ Test that the header values are updated correctly.
+    """ Tests that cropping works, and updates header values related to 
+    pixel positions and data shapes correctly, for 3D data.
     """
 
     test_dataset = make_test_dataset(shape=[100,100],centxy=[49.5,49.5])
@@ -167,7 +167,8 @@ def test_header_updates_2d():
         raise Exception("Frame dq header kw NAXIS2 not updated correctly.")
 
 def test_header_updates_3d():
-    """ Test that the header values are updated correctly.
+    """ Tests that cropping works, and updates header values related to pixel 
+    positions and data shapes correctly, for 3D data.
     """
 
     test_dataset = make_test_dataset(shape=[3,100,100],centxy=[49.5,49.5])
@@ -209,12 +210,34 @@ def test_header_updates_3d():
     if not cropped_test_dataset[0].err_hdr["NAXIS3"] == 3:
         raise Exception("Frame err header kw NAXIS3 not updated correctly.")
 
+def test_non_nfov_input():
+    """ Crop function is not configured for non-NFOV observations and should
+    fail if the Lyot stop is not in the narrow FOV position, unless the desired
+    image size is provided manually.
+    """
+
+    test_dataset = make_test_dataset(shape=[100,100],centxy=[50.5,50.5])
+    for frame in test_dataset:
+        frame.pri_hdr['LSAMNAME'] = 'WFOV'
+
+    try:
+        _ = crop(test_dataset,sizexy=20,centerxy=None)
+    except:
+        raise ValueError('Cropping a non-NFOV observation failed even though sizexy was provided')
+
+
+    with pytest.raises(UserWarning):
+        _ = crop(test_dataset,sizexy=None,centerxy=None)
+
+
 if __name__ == "__main__":
     test_2d_square_center_crop()
     test_2d_square_offcenter_crop()
     test_2d_rect_offcenter_crop()
-    test_edge_of_FOV()
-    test_outside_FOV()
+    test_3d_rect_offcenter_crop()
+    test_edge_of_detector()
+    test_outside_detector_edge()
     test_nonhalfinteger_centxy()
     test_header_updates_2d()
     test_header_updates_3d()
+    test_non_nfov_input()