From db206977f7921a863aa4f3a281bf034a4f04f716 Mon Sep 17 00:00:00 2001
From: Claudia Comito <c.comito@fz-juelich.de>
Date: Thu, 4 Jun 2020 12:00:05 +0200
Subject: [PATCH 1/5] Implemented fliplr()

---
 heat/core/manipulations.py | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/heat/core/manipulations.py b/heat/core/manipulations.py
index a708a5d276..739b1b27f7 100644
--- a/heat/core/manipulations.py
+++ b/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.

From 1bd08957743e45b326a98460e855964ca414817a Mon Sep 17 00:00:00 2001
From: Claudia Comito <c.comito@fz-juelich.de>
Date: Thu, 4 Jun 2020 12:18:07 +0200
Subject: [PATCH 2/5] Added tests for fliplr.

---
 heat/core/tests/test_manipulations.py | 39 +++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/heat/core/tests/test_manipulations.py b/heat/core/tests/test_manipulations.py
index 9019b28f2e..5778d4a567 100644
--- a/heat/core/tests/test_manipulations.py
+++ b/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)

From 7760f16ec33019dfd3f704a69ec9563efedbf47e Mon Sep 17 00:00:00 2001
From: Claudia Comito <c.comito@fz-juelich.de>
Date: Thu, 4 Jun 2020 12:29:24 +0200
Subject: [PATCH 3/5] updated changelog

---
 CHANGELOG.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9843d5a8dc..75cfeb0a5e 100644
--- a/CHANGELOG.md
+++ b/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

From f4dba28e92ba651f140377183d7f3647a1baa4f2 Mon Sep 17 00:00:00 2001
From: Claudia Comito <c.comito@fz-juelich.de>
Date: Thu, 4 Jun 2020 13:41:26 +0200
Subject: [PATCH 4/5] travis tricks

---
 .travis.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.travis.yml b/.travis.yml
index 618bcc1371..f4594989fa 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,6 @@
 language: python
 python:
-  - "3.6"
+  - "3.7"
 
 services:
   - docker

From 415095e8d9eddb8318427b14b44068d64e59f4f7 Mon Sep 17 00:00:00 2001
From: Claudia Comito <c.comito@fz-juelich.de>
Date: Thu, 4 Jun 2020 13:50:44 +0200
Subject: [PATCH 5/5] undo travis tricks

---
 .travis.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.travis.yml b/.travis.yml
index f4594989fa..618bcc1371 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,6 @@
 language: python
 python:
-  - "3.7"
+  - "3.6"
 
 services:
   - docker