Merge branch 'rot_math' into fix_merge_rotations

pennylane/transforms/optimization/optimization_utils.py

@@ -41,17 +41,17 @@ def find_next_gate(wires, op_list):
  return next_gate_idx
 
 
-def _try_no_fuse(angles1, angles2):
+def _try_no_fuse(angles_1, angles_2):
  """Try to combine rotation angles without trigonometric identities
  if some angles in the input angles vanish."""
- dummy_sum = angles1 + angles2
+ angles_1 = qml.math.asarray(angles_1)
+ angles_2 = qml.math.asarray(angles_2)
+ # This sum is only computed to obtain a dtype-coerced object that respects
+ # TensorFlow's coercion rules between Python/NumPy objects and TF objects.
+ _sum = angles_1 + angles_2
  # moveaxis required for batched inputs
- phi1, theta1, omega1 = qml.math.moveaxis(
- qml.math.cast_like(qml.math.asarray(angles1), dummy_sum), -1, 0
- )
- phi2, theta2, omega2 = qml.math.moveaxis(
- qml.math.cast_like(qml.math.asarray(angles2), dummy_sum), -1, 0
- )
+ phi1, theta1, omega1 = qml.math.moveaxis(qml.math.cast_like(angles_1, _sum), -1, 0)
+ phi2, theta2, omega2 = qml.math.moveaxis(qml.math.cast_like(angles_2, _sum), -1, 0)
 
  if qml.math.allclose(omega1 + phi2, 0.0):
  return qml.math.stack([phi1, theta1 + theta2, omega2])
@@ -68,7 +68,7 @@ def _try_no_fuse(angles1, angles2):
  return None
 
 
-def fuse_rot_angles(angles1, angles2):
+def fuse_rot_angles(angles_1, angles_2):
  r"""Compute the set of rotation angles that is equivalent to performing
  two successive ``qml.Rot`` operations.
 
@@ -108,18 +108,18 @@ def fuse_rot_angles(angles1, angles2):
  """
 
  if not (
- qml.math.is_abstract(angles1)
- or qml.math.is_abstract(angles2)
- or qml.math.requires_grad(angles1)
- or qml.math.requires_grad(angles2)
+ qml.math.is_abstract(angles_1)
+ or qml.math.is_abstract(angles_2)
+ or qml.math.requires_grad(angles_1)
+ or qml.math.requires_grad(angles_2)
  ):
- fused_angles = _try_no_fuse(angles1, angles2)
+ fused_angles = _try_no_fuse(angles_1, angles_2)
  if fused_angles is not None:
  return fused_angles
 
  # moveaxis required for batched inputs
- phi1, theta1, omega1 = qml.math.moveaxis(qml.math.asarray(angles1), -1, 0)
- phi2, theta2, omega2 = qml.math.moveaxis(qml.math.asarray(angles2), -1, 0)
+ phi1, theta1, omega1 = qml.math.moveaxis(qml.math.asarray(angles_1), -1, 0)
+ phi2, theta2, omega2 = qml.math.moveaxis(qml.math.asarray(angles_2), -1, 0)
  c1, c2 = qml.math.cos(theta1 / 2), qml.math.cos(theta2 / 2)
  s1, s2 = qml.math.sin(theta1 / 2), qml.math.sin(theta2 / 2)