Merge pull request #862 from helmholtz-analytics/feature/861-signbit

add signbit

CHANGELOG.md

@@ -12,6 +12,8 @@
 ### Linear Algebra
 - [#840](https://github.com/helmholtz-analytics/heat/pull/840) New feature: `vecdot()`
 - [#846](https://github.com/helmholtz-analytics/heat/pull/846) New features `norm`, `vector_norm`, `matrix_norm`
+### Logical
+- [#862](https://github.com/helmholtz-analytics/heat/pull/862) New feature `signbit`
 ### Manipulations
 - [#829](https://github.com/helmholtz-analytics/heat/pull/829) New feature: `roll`
 - [#853](https://github.com/helmholtz-analytics/heat/pull/853) New Feature: `swapaxes`

heat/core/logical.py

@@ -31,6 +31,7 @@
     "logical_not",
     "logical_or",
     "logical_xor",
+    "signbit",
 ]
 
 
@@ -508,3 +509,23 @@ def sanitize_input_type(
 
     else:
         return x, y
+
+
+def signbit(x: DNDarray, out: Optional[DNDarray] = None) -> DNDarray:
+    """
+    Checks if signbit is set element-wise (less than zero).
+
+    Parameters
+    ----------
+    x : DNDarray
+        The input array.
+    out : DNDarray, optional
+        The output array.
+
+    Examples
+    --------
+    >>> a = ht.array([2, -1.3, 0])
+    >>> ht.signbit(a)
+    DNDarray([False,  True, False], dtype=ht.bool, device=cpu:0, split=None)
+    """
+    return _operations.__local_op(torch.signbit, x, out, no_cast=True)

heat/core/tests/test_logical.py

@@ -481,3 +481,14 @@ def test_logical_xor(self):
                 ht.array([[False, False], [False, False]]),
             )
         )
+
+    def test_signbit(self):
+        a = ht.array([2, -1.3, 0, -5], split=0)
+
+        sb = ht.signbit(a)
+        cmp = ht.array([False, True, False, True])
+
+        self.assertEqual(sb.dtype, ht.bool)
+        self.assertEqual(sb.split, 0)
+        self.assertEqual(sb.device, a.device)
+        self.assertTrue(ht.equal(sb, cmp))