【Hackathon 6th No. 7】Add sinc / sinc_ API to Paddle -part (#63521)

NKNaN · web-flow · commit 5efe6356feec · 2024-05-16T09:57:08.000+08:00
* add sinc

* fix float16

* remove cpu fp16 test

* fix tolerance

* update test

* fix timeout

* fix fp16 test

* fix fp16 test

* fix fp16 test

* add dtype check

* update check dtype

* update test

* fix init

* add bfloat16 test and fix underflow problem

* rerun ci

* fix test

* fix test

* fix bf16

* update test

* update test

* update test

* rerun ci

* fix bf16 test

* rerun ci

* add gradient test

* add gradient test
diff --git a/python/paddle/__init__.py b/python/paddle/__init__.py
@@ -493,6 +493,8 @@
     signbit,
     sin,
     sin_,
+    sinc,
+    sinc_,
     sinh,
     sinh_,
     sqrt,
@@ -811,6 +813,8 @@
     'standard_gamma',
     'sinh',
     'sinh_',
+    'sinc',
+    'sinc_',
     'round',
     'DataParallel',
     'argmin',
diff --git a/python/paddle/tensor/__init__.py b/python/paddle/tensor/__init__.py
@@ -379,6 +379,8 @@
     signbit,
     sin,
     sin_,
+    sinc,
+    sinc_,
     sinh,
     sinh_,
     sqrt,
@@ -525,6 +527,7 @@
     'scale_',
     'sign',
     'sin',
+    'sinc',
     'sinh',
     'sqrt',
     'sqrt_',
@@ -802,6 +805,7 @@
     'cos_',
     'cosh_',
     'sin_',
+    'sinc_',
     'sinh_',
     'acosh_',
     'asinh_',
diff --git a/python/paddle/tensor/math.py b/python/paddle/tensor/math.py
@@ -7744,7 +7744,7 @@ def isposinf(x, name=None):
         name (str, optional): Name for the operation (optional, default is None). For more information, please refer to :ref:`api_guide_Name`.
 
     Returns:
-        out (Tensor): The output Tensor. Each element of output indicates whether the input element is positive infinity or not.
+        out (Tensor), The output Tensor. Each element of output indicates whether the input element is positive infinity or not.
 
     Examples:
         .. code-block:: python
@@ -7791,7 +7791,7 @@ def isneginf(x, name=None):
         name (str, optional): Name for the operation (optional, default is None). For more information, please refer to :ref:`api_guide_Name`.
 
     Returns:
-        out (Tensor): The output Tensor. Each element of output indicates whether the input element is negative infinity or not.
+        out (Tensor), The output Tensor. Each element of output indicates whether the input element is negative infinity or not.
 
     Examples:
         .. code-block:: python
@@ -7838,7 +7838,7 @@ def isreal(x, name=None):
         name (str, optional): Name for the operation (optional, default is None). For more information, please refer to :ref:`api_guide_Name`.
 
     Returns:
-        out (Tensor): The output Tensor. Each element of output indicates whether the input element is a real number or not.
+        out (Tensor), The output Tensor. Each element of output indicates whether the input element is a real number or not.
 
     Examples:
         .. code-block:: python
@@ -7876,3 +7876,87 @@ def isreal(x, name=None):
         return paddle.ones_like(x, dtype='bool')
 
     return paddle.equal(paddle.imag(x), 0)
+
+
+def sinc(x, name=None):
+    r"""
+    Calculate the normalized sinc of ``x`` elementwise.
+
+    .. math::
+
+        out_i =
+        \left\{
+        \begin{aligned}
+        &1 & \text{ if $x_i = 0$} \\
+        &\frac{\sin(\pi x_i)}{\pi x_i} & \text{ otherwise}
+        \end{aligned}
+        \right.
+
+    Args:
+        x (Tensor): The input Tensor. Must be one of the following types: bfloat16, float16, float32, float64.
+        name (str, optional): Name for the operation (optional, default is None). For more information, please refer to :ref:`api_guide_Name`.
+
+    Returns:
+        out (Tensor), The Tensor of elementwise-computed normalized sinc result.
+
+    Examples:
+        .. code-block:: python
+
+            >>> import paddle
+            >>> paddle.set_device('cpu')
+            >>> paddle.seed(100)
+            >>> x = paddle.rand([2,3], dtype='float32')
+            >>> res = paddle.sinc(x)
+            >>> print(res)
+            Tensor(shape=[2, 3], dtype=float32, place=Place(cpu), stop_gradient=True,
+            [[0.56691176, 0.93089867, 0.99977750],
+             [0.61639023, 0.79618412, 0.89171958]])
+    """
+    if not isinstance(x, (paddle.Tensor, Variable, paddle.pir.Value)):
+        raise TypeError(f"x must be tensor type, but got {type(x)}")
+
+    check_variable_and_dtype(
+        x,
+        "x",
+        [
+            'uint16',
+            'float16',
+            'float32',
+            'float64',
+        ],
+        "sinc",
+    )
+
+    tmp = paddle.where(x != 0, x, paddle.full_like(x, 1.0e-20))
+    tmp = paddle.multiply(tmp, paddle.to_tensor(math.pi, dtype=x.dtype))
+    tmp = paddle.divide(tmp.sin(), tmp)
+    return paddle.where(~paddle.isnan(tmp), tmp, paddle.full_like(x, 1.0))
+
+
+@inplace_apis_in_dygraph_only
+def sinc_(x, name=None):
+    r"""
+    Inplace version of ``sinc`` API, the output Tensor will be inplaced with input ``x``.
+    Please refer to :ref:`api_paddle_sinc`.
+    """
+    if not isinstance(x, (paddle.Tensor, Variable)):
+        raise TypeError(f"x must be tensor type, but got {type(x)}")
+
+    check_variable_and_dtype(
+        x,
+        "x",
+        [
+            'uint16',
+            'float16',
+            'float32',
+            'float64',
+        ],
+        "sinc_",
+    )
+
+    paddle.where_(x != 0, x, paddle.full_like(x, 1.0e-20))
+    paddle.multiply_(x, paddle.to_tensor(math.pi, dtype=x.dtype))
+    tmp = paddle.clone(x)
+    paddle.sin_(x)
+    paddle.divide_(x, tmp)
+    return paddle.where(~paddle.isnan(x), x, paddle.full_like(x, 1.0))
diff --git a/test/legacy_test/test_sinc.py b/test/legacy_test/test_sinc.py
