testing: Add test for new dexela_2923_quad distortion

Author: ChristosT

tests/test_distortion.py

@@ -1,9 +1,10 @@
 from hexrd.distortion.dexela_2923 import Dexela_2923, _find_quadrant
+from hexrd.distortion.dexela_2923_quad import Dexela_2923_quad
 from hexrd import constants
 import numpy as np
 
 
-def test_distortion():
+def test_dexela_2923_distortion():
     pts = np.random.randn(16, 2)
     qi = _find_quadrant(pts)
 
@@ -25,3 +26,40 @@ def test_distortion():
         raise RuntimeError("distortion apply failed!")
     if not np.all(abs(result_inv + ptile) <= constants.ten_epsf):
         raise RuntimeError("distortion apply_inverse failed!")
+
+
+def test_dexela_2923_quad_distortion():
+    pts = np.random.randn(16, 2)
+    qi = _find_quadrant(pts)
+
+    # test trivial
+    params = np.zeros(10)
+    dc = Dexela_2923(params)
+    if not np.all(dc.apply(pts) - pts == 0.0):
+        raise RuntimeError("distortion apply failed!")
+    if not np.all(dc.apply_inverse(pts) - pts == 0.0):
+        raise RuntimeError("distortion apply_inverse failed!")
+
+    # test non-trivial
+
+    # this is the original test submited in
+    # https://github.com/HEXRD/hexrd/issues/749
+    # but it does not currently work. First, params needs to be of size 6, but
+    # this break vstack command bellow. Not sure how to adapt it.
+    # params = np.random.randn(10)
+    # dc = Dexela_2923_quad(params)
+    # ptile = np.vstack([params.reshape(4, 2)[j - 1, :] for j in qi])
+    # result = dc.apply(pts) - pts
+    # result_inv = dc.apply_inverse(pts) - pts
+    # if not np.all(abs(result - ptile) <= constants.epsf):
+    #    raise RuntimeError("distortion apply failed!")
+    # if not np.all(abs(result_inv + ptile) <= constants.epsf):
+    #    raise RuntimeError("distortion apply_inverse failed!")
+    # return True
+
+    # we simply test that apply and reverse cancel each other
+    params = np.random.randn(6)
+    dc = Dexela_2923_quad(params)
+    result = dc.apply_inverse(dc.apply(pts))
+    if not np.all(abs(result - pts) <= 100 * constants.epsf):
+        raise RuntimeError("distortion apply_inverse(apply) failed!")