【Hackathon 5th No.14】Add combinations API to Paddle

python/paddle/tensor/math.py

@@ -6953,30 +6953,21 @@ def combinations(x, r=2, with_replacement=False, name=None):
         .. code-block:: python
 
             >>> import paddle
-
-            >>> # example1
-            >>> x = paddle.to_tensor([1, 2, 3], dtype='float32')
-            >>> y = paddle.to_tensor([2, 3, 4], dtype='int32')
-            >>> res = paddle.ldexp(x, y)
+            >>> x = paddle.to_tensor([1, 2, 3], dtype='int32')
+            >>> res = paddle.combinations(x)
             >>> print(res)
-            Tensor(shape=[3], dtype=float32, place=Place(cpu), stop_gradient=True,
-            [4. , 16., 48.])
-
-            >>> # example2
-            >>> x = paddle.to_tensor([1, 2, 3], dtype='float32')
-            >>> y = paddle.to_tensor([2], dtype='int32')
-            >>> res = paddle.ldexp(x, y)
-            >>> print(res)
-            Tensor(shape=[3], dtype=float32, place=Place(cpu), stop_gradient=True,
-            [4. , 8. , 12.])
+            Tensor(shape=[3, 2], dtype=int32, place=Place(gpu:0), stop_gradient=True,
+                   [[1, 2],
+                    [1, 3],
+                    [2, 3]])
 
     """
     if len(x.shape) != 1:
         raise TypeError(f"Expect a 1-D vector, but got x shape {x.shape}")
     if not isinstance(r, int) or r < 0:
         raise ValueError(f"Expect a non-negative int, but got r={r}")
 
-    if r == 0:
+    if r == 0 or r > x.shape[0]:
         return paddle.empty([0], dtype=x.dtype)
 
     if r > 1:

test/legacy_test/test_combinations.py

@@ -23,7 +23,7 @@
 paddle.enable_static()
 
 
-def convert_combinations_to_array(x, r, with_replacement):
+def convert_combinations_to_array(x, r=2, with_replacement=False):
     if r == 0:
         return np.array([]).astype(x.dtype)
     if with_replacement:
@@ -114,3 +114,11 @@ def modify_setting(self):
         self.x_shape = [10]
         self.r = 0
         self.with_replacement = True
+
+
+class TestIndexFillAPI3(TestCombinationsAPIBase):
+    def modify_setting(self):
+        self.dtype_np = 'float32'
+        self.x_shape = [0]
+        self.r = 10
+        self.with_replacement = False