added test for solve3DTransform

pyqtgraph/functions.py

@@ -568,16 +568,25 @@ def transformCoordinates(tr, coords, transpose=False):
 def solve3DTransform(points1, points2):
     """
     Find a 3D transformation matrix that maps points1 onto points2.
-    Points must be specified as a list of 4 Vectors.
+    Points must be specified as either lists of 4 Vectors or 
+    (4, 3) arrays.
     """
     import numpy.linalg
-    A = np.array([[points1[i].x(), points1[i].y(), points1[i].z(), 1] for i in range(4)])
-    B = np.array([[points2[i].x(), points2[i].y(), points2[i].z(), 1] for i in range(4)])
+    pts = []
+    for inp in (points1, points2):
+        if isinstance(inp, np.ndarray):
+            A = np.empty((4,4), dtype=float)
+            A[:,:3] = inp[:,:3]
+            A[:,3] = 1.0
+        else:
+            A = np.array([[inp[i].x(), inp[i].y(), inp[i].z(), 1] for i in range(4)])
+        pts.append(A)
     
     ## solve 3 sets of linear equations to determine transformation matrix elements
     matrix = np.zeros((4,4))
     for i in range(3):
-        matrix[i] = numpy.linalg.solve(A, B[:,i])  ## solve Ax = B; x is one row of the desired transformation matrix
+        ## solve Ax = B; x is one row of the desired transformation matrix
+        matrix[i] = numpy.linalg.solve(pts[0], pts[1][:,i])  
     
     return matrix
     

pyqtgraph/tests/test_functions.py

@@ -0,0 +1,21 @@
+import pyqtgraph as pg
+import numpy as np
+from numpy.testing import assert_array_almost_equal, assert_almost_equal
+
+np.random.seed(12345)
+
+def testSolve3D():
+    p1 = np.array([[0,0,0,1],
+                   [1,0,0,1],
+                   [0,1,0,1],
+                   [0,0,1,1]], dtype=float)
+    
+    # transform points through random matrix
+    tr = np.random.normal(size=(4, 4))
+    tr[3] = (0,0,0,1)
+    p2 = np.dot(tr, p1.T).T[:,:3]
+    
+    # solve to see if we can recover the transformation matrix.
+    tr2 = pg.solve3DTransform(p1, p2)
+    
+    assert_array_almost_equal(tr[:3], tr2[:3])