Make FGM work for exotic dtypes. Some black-ing, pep8-ing. Fix broken…

… test.

cleverhans/torch/attacks/fast_gradient_method.py

@@ -71,7 +71,9 @@ def fast_gradient_method(
 
     # x needs to be a leaf variable, of floating point type and have requires_grad being True for
     # its grad to be computed and stored properly in a backward call
-    x = x.clone().detach().to(torch.float).requires_grad_(True)
+    # kylematoba: probably don't need this, but I'll add it here to respect the intention of the earlier cast
+    assert torch.is_floating_point(x)
+    x = x.clone().detach().to(x.dtype).requires_grad_(True)
     if y is None:
         # Using model predictions as ground truth to avoid label leaking
         _, y = torch.max(model_fn(x), 1)

cleverhans/torch/attacks/hop_skip_jump_attack.py

@@ -89,7 +89,7 @@ def decision_function(images):
             images = torch.clamp(images, clip_min, clip_max)
             prob = []
             for i in range(0, len(images), batch_size):
-                batch = images[i : i + batch_size]
+                batch = images[i: i + batch_size]
                 prob_i = model_fn(batch)
                 prob.append(prob_i)
             prob = torch.cat(prob, dim=0)
@@ -214,7 +214,7 @@ def decision_function(images):
 
 
 def compute_distance(x_ori, x_pert, constraint=2):
-    """ Compute the distance between two images. """
+    """Compute the distance between two images."""
     if constraint == 2:
         dist = torch.norm(x_ori - x_pert, p=2)
     elif constraint == np.inf:
@@ -225,7 +225,7 @@ def compute_distance(x_ori, x_pert, constraint=2):
 def approximate_gradient(
     decision_function, sample, num_evals, delta, constraint, shape, clip_min, clip_max
 ):
-    """ Gradient direction estimation """
+    """Gradient direction estimation"""
     # Generate random vectors.
     noise_shape = [num_evals] + list(shape)
     if constraint == 2:
@@ -260,7 +260,7 @@ def approximate_gradient(
 
 
 def project(original_image, perturbed_images, alphas, shape, constraint):
-    """ Projection onto given l2 / linf balls in a batch. """
+    """Projection onto given l2 / linf balls in a batch."""
     alphas = alphas.view((alphas.shape[0],) + (1,) * (len(shape) - 1))
     if constraint == 2:
         projected = (1 - alphas) * original_image + alphas * perturbed_images
@@ -274,7 +274,7 @@ def project(original_image, perturbed_images, alphas, shape, constraint):
 def binary_search_batch(
     original_image, perturbed_images, decision_function, shape, constraint, theta
 ):
-    """ Binary search to approach the boundary. """
+    """Binary search to approach the boundary."""
 
     # Compute distance between each of perturbed image and original image.
     dists_post_update = torch.stack(

cleverhans/torch/tests/test_attacks.py

@@ -489,6 +489,7 @@ def test_clips(self):
             if norm == 1:
                 self.assertRaises(
                     NotImplementedError,
+                    self.attack,
                     model_fn=self.model,
                     x=self.normalized_x,
                     eps=0.3,
@@ -1045,3 +1046,4 @@ def test_grad_sparsity_checks(self):
         with self.assertRaises(ValueError) as context:
             gs = torch.empty(101).uniform_(90, 99)
             self.generate_adversarial_examples(sanity_checks=False, grad_sparsity=gs)
+

cleverhans/torch/utils.py

@@ -84,7 +84,6 @@ def optimize_linear(grad, eps, norm=np.inf):
         # Take sign of gradient
         optimal_perturbation = torch.sign(grad)
     elif norm == 1:
-        abs_grad = torch.abs(grad)
         sign = torch.sign(grad)
         red_ind = list(range(1, len(grad.size())))
         abs_grad = torch.abs(grad)