1 files changed, 71 insertions, 0 deletions
diff --git a/tensorflow/python/kernel_tests/gather_op_test.py b/tensorflow/python/kernel_tests/gather_op_test.py
new file mode 100644
index 0000000000..39e97531d2
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+++ b/tensorflow/python/kernel_tests/gather_op_test.py
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+"""Tests for tensorflow.ops.tf.gather."""
+import tensorflow.python.platform
+
+import numpy as np
+import tensorflow as tf
+
+
+class GatherTest(tf.test.TestCase):
+
+  def testScalar1D(self):
+    with self.test_session():
+      params = tf.constant([0, 1, 2, 3, 7, 5])
+      indices = tf.constant(4)
+      gather_t = tf.gather(params, indices)
+      gather_val = gather_t.eval()
+    self.assertAllEqual(7, gather_val)
+    self.assertEqual([], gather_t.get_shape())
+
+  def testScalar2D(self):
+    with self.test_session():
+      params = tf.constant([[0, 1, 2], [3, 4, 5], [6, 7, 8],
+                                     [9, 10, 11], [12, 13, 14]])
+      indices = tf.constant(2)
+      gather_t = tf.gather(params, indices)
+      gather_val = gather_t.eval()
+    self.assertAllEqual([6, 7, 8], gather_val)
+    self.assertEqual([3], gather_t.get_shape())
+
+  def testSimpleTwoD32(self):
+    with self.test_session():
+      params = tf.constant([[0, 1, 2], [3, 4, 5], [6, 7, 8],
+                                     [9, 10, 11], [12, 13, 14]])
+      indices = tf.constant([0, 4, 0, 2])
+      gather_t = tf.gather(params, indices)
+      gather_val = gather_t.eval()
+    self.assertAllEqual([[0, 1, 2], [12, 13, 14], [0, 1, 2], [6, 7, 8]],
+                        gather_val)
+    self.assertEqual([4, 3], gather_t.get_shape())
+
+  def testHigherRank(self):
+    np.random.seed(1)
+    shape = (4, 3, 2)
+    params = np.random.randn(*shape)
+    indices = np.random.randint(shape[0], size=15).reshape(3, 5)
+    with self.test_session():
+      tf_params = tf.constant(params)
+      tf_indices = tf.constant(indices)
+      gather = tf.gather(tf_params, tf_indices)
+      self.assertAllEqual(params[indices], gather.eval())
+      self.assertEqual(indices.shape + params.shape[1:], gather.get_shape())
+      # Test gradients
+      gather_grad = np.random.randn(*gather.get_shape().as_list())
+      params_grad, indices_grad = tf.gradients(gather, [tf_params, tf_indices],
+                                               gather_grad)
+      self.assertEqual(indices_grad, None)
+      self.assertEqual(type(params_grad), tf.IndexedSlices)
+      params_grad = tf.convert_to_tensor(params_grad)
+      correct_params_grad = np.zeros(shape)
+      for i, g in zip(indices.ravel(), gather_grad.reshape((15,) + shape[1:])):
+        correct_params_grad[i] += g
+      self.assertAllEqual(correct_params_grad, params_grad.eval())
+
+  def testUnknownIndices(self):
+    params = tf.constant([[0, 1, 2]])
+    indices = tf.placeholder(tf.int32)
+    gather_t = tf.gather(params, indices)
+    self.assertEqual(None, gather_t.get_shape())
+
+
+if __name__ == "__main__":
+  tf.test.main()