Merge pull request #580 from helmholtz-analytics/features/35-fliplr

Features/35 fliplr

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Pending Additions
 
 - [#573](https://github.com/helmholtz-analytics/heat/pull/573) Bugfix: matmul fixes: early out for 2 vectors, remainders not added if inner block is 1 for split 10 case
+- [#580](https://github.com/helmholtz-analytics/heat/pull/580) New feature: fliplr()
 
 
 # v0.4.0

heat/core/manipulations.py

@@ -18,6 +18,7 @@
     "expand_dims",
     "flatten",
     "flip",
+    "fliplr",
     "flipud",
     "hstack",
     "reshape",
@@ -702,6 +703,35 @@ def flip(a, axis=None):
     return res
 
 
+def fliplr(a):
+    """
+        Flip array in the left/right direction. If a.ndim > 2, flip along dimension 1.
+
+        Parameters
+        ----------
+        a: ht.DNDarray
+            Input array to be flipped, must be at least 2-D
+
+        Returns
+        -------
+        res: ht.DNDarray
+            The flipped array.
+
+        Examples
+        --------
+        >>> a = ht.array([[0,1],[2,3]])
+        >>> ht.fliplr(a)
+        tensor([[1, 0],
+                [3, 2]])
+
+        >>> b = ht.array([[0,1,2],[3,4,5]], split=0)
+        >>> ht.fliplr(b)
+        (1/2) tensor([[2, 1, 0]])
+        (2/2) tensor([[5, 4, 3]])
+    """
+    return flip(a, 1)
+
+
 def flipud(a):
     """
         Flip array in the up/down direction.

heat/core/tests/test_manipulations.py

@@ -827,6 +827,45 @@ def test_flip(self):
         )
         self.assertTrue(ht.equal(ht.flip(a, [1, 2]), r_a))
 
+    def test_fliplr(self):
+        b = ht.array([[1, 2], [3, 4]], device=ht_device)
+        r_b = ht.array([[2, 1], [4, 3]], device=ht_device)
+        self.assertTrue(ht.equal(ht.fliplr(b), r_b))
+
+        # splitted
+        c = ht.array(
+            [[[0, 1], [2, 3]], [[4, 5], [6, 7]], [[8, 9], [10, 11]], [[12, 13], [14, 15]]],
+            split=0,
+            device=ht_device,
+        )
+        r_c = ht.array(
+            [[[2, 3], [0, 1]], [[6, 7], [4, 5]], [[10, 11], [8, 9]], [[14, 15], [12, 13]]],
+            split=0,
+            device=ht_device,
+        )
+        self.assertTrue(ht.equal(ht.fliplr(c), r_c))
+
+        c = ht.array(
+            [[[0, 1], [2, 3]], [[4, 5], [6, 7]], [[8, 9], [10, 11]], [[12, 13], [14, 15]]],
+            split=1,
+            device=ht_device,
+            dtype=ht.float32,
+        )
+        self.assertTrue(ht.equal(ht.resplit(ht.fliplr(c), 0), r_c))
+
+        c = ht.array(
+            [[[0, 1], [2, 3]], [[4, 5], [6, 7]], [[8, 9], [10, 11]], [[12, 13], [14, 15]]],
+            split=2,
+            device=ht_device,
+            dtype=ht.int8,
+        )
+        self.assertTrue(ht.equal(ht.resplit(ht.fliplr(c), 0), r_c))
+
+        # test exception
+        a = ht.arange(10, device=ht_device)
+        with self.assertRaises(IndexError):
+            ht.fliplr(a)
+
     def test_flipud(self):
         a = ht.array([1, 2], device=ht_device)
         r_a = ht.array([2, 1], device=ht_device)