Add the inverse trigonometric function

test=develop

paddle/fluid/API.spec

@@ -292,6 +292,7 @@ paddle.fluid.layers.sigmoid (ArgSpec(args=['x', 'name'], varargs=None, keywords=
 paddle.fluid.layers.logsigmoid (ArgSpec(args=['x', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', '81ccb7acafd06c7728e11581f5d342e3'))
 paddle.fluid.layers.exp (ArgSpec(args=['x', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', 'e6b3e769413d96aab4176f96db25984b'))
 paddle.fluid.layers.tanh (ArgSpec(args=['x', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', 'e9d586a0b5bd05f67ee78048f9d503b6'))
+paddle.fluid.layers.atan (ArgSpec(args=['x', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', '7ca26a8235099486bdf243754439c6b6'))
 paddle.fluid.layers.tanh_shrink (ArgSpec(args=['x', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', '1e521554b9fdda9061ec6d306f0709b7'))
 paddle.fluid.layers.softshrink (ArgSpec(args=['x', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', '9eef31597bbafa2bd49691e072296e13'))
 paddle.fluid.layers.sqrt (ArgSpec(args=['x', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', '072a8541e0f632366bba10f67cb0db27'))
@@ -299,7 +300,9 @@ paddle.fluid.layers.abs (ArgSpec(args=['x', 'name'], varargs=None, keywords=None
 paddle.fluid.layers.ceil (ArgSpec(args=['x', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', 'c75d67dc5fe28f68e4cfffead4f698ad'))
 paddle.fluid.layers.floor (ArgSpec(args=['x', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', '647b16c5da5ef909649ae02abb434973'))
 paddle.fluid.layers.cos (ArgSpec(args=['x', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', '485f2686bcc2fe37a4bd893769c8a3e2'))
+paddle.fluid.layers.acos (ArgSpec(args=['x', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', 'c721122352acfc1853bffadf2d59103b'))
 paddle.fluid.layers.sin (ArgSpec(args=['x', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', '01f1766aa76eff1df30147505b59f7c4'))
+paddle.fluid.layers.asin (ArgSpec(args=['x', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', '0619b891e80f419b28016cde3d106c68'))
 paddle.fluid.layers.round (ArgSpec(args=['x', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', 'b47f5da13913d3e56bdb1e612a73f3f2'))
 paddle.fluid.layers.reciprocal (ArgSpec(args=['x', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', 'cc6ac2f14f03c52aaa83a59bf83b8d26'))
 paddle.fluid.layers.square (ArgSpec(args=['x', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', '48dfb45d773dbc30126c3a7f777de5ee'))

paddle/fluid/operators/activation_op.cc

@@ -269,6 +269,27 @@ $$out = \\frac{x}{1 + \|x\|}$$
 
 )DOC";
 
+UNUSED constexpr char AcosDoc[] = R"DOC(
+Arccosine Activation Operator.
+
+$${out}_{i} = \cos^{-1}({input}_{i})$$
+
+)DOC";
+
+UNUSED constexpr char AsinDoc[] = R"DOC(
+Arcsine Activation Operator.
+
+$out = \sin^{-1}({input}_{i})$
+
+)DOC";
+
+UNUSED constexpr char AtanDoc[] = R"DOC(
+Arctanh Activation Operator.
+
+$out = \tanh^{-1}({input}_{i})$
+
+)DOC";
+
 class LeakyReluOpMaker : public framework::OpProtoAndCheckerMaker {
  public:
   void Make() override {
@@ -494,13 +515,16 @@ REGISTER_ACTIVATION_OP_MAKER(Exp, ExpDoc);
 REGISTER_ACTIVATION_OP_MAKER(Relu, ReluDoc);
 REGISTER_ACTIVATION_OP_MAKER(Gelu, GeluDoc);
 REGISTER_ACTIVATION_OP_MAKER(Tanh, TanhDoc);
+REGISTER_ACTIVATION_OP_MAKER(Atan, AtanDoc);
 REGISTER_ACTIVATION_OP_MAKER(TanhShrink, TanhShrinkDoc);
 REGISTER_ACTIVATION_OP_MAKER(Sqrt, SqrtDoc);
 REGISTER_ACTIVATION_OP_MAKER(Abs, AbsDoc);
 REGISTER_ACTIVATION_OP_MAKER(Ceil, CeilDoc);
 REGISTER_ACTIVATION_OP_MAKER(Floor, FloorDoc);
 REGISTER_ACTIVATION_OP_MAKER(Cos, CosDoc);
+REGISTER_ACTIVATION_OP_MAKER(Acos, AcosDoc);
 REGISTER_ACTIVATION_OP_MAKER(Sin, SinDoc);
+REGISTER_ACTIVATION_OP_MAKER(Asin, AsinDoc);
 REGISTER_ACTIVATION_OP_MAKER(Round, RoundDoc);
 REGISTER_ACTIVATION_OP_MAKER(Reciprocal, ReciprocalDoc);
 REGISTER_ACTIVATION_OP_MAKER(Log, LogDoc);
@@ -543,7 +567,10 @@ namespace ops = paddle::operators;
   __macro(SoftShrink, softshrink);   \
   __macro(Abs, abs);                 \
   __macro(Cos, cos);                 \
+  __macro(Acos, acos);               \
   __macro(Sin, sin);                 \
+  __macro(Asin, asin);               \
+  __macro(Atan, atan);               \
   __macro(Round, round);             \
   __macro(Log, log);                 \
   __macro(Square, square);           \

paddle/fluid/operators/activation_op.h

@@ -40,8 +40,7 @@ namespace operators {
  */
 static std::unordered_set<std::string> InplaceOpSet = {
     "sigmoid", "exp",        "relu",  "tanh",      "sqrt",        "ceil",
-    "floor",   "reciprocal", "relu6", "soft_relu", "hard_sigmoid",
-};
+    "floor",   "reciprocal", "relu6", "soft_relu", "hard_sigmoid"};
 
 static bool IsInplace(const std::string& op) {
   bool inplace = InplaceOpSet.count(op);
@@ -553,6 +552,101 @@ struct SinFunctor : public BaseActivationFunctor<T> {
   }
 };
 
+template <typename T>
+struct Acos {
+  HOSTDEVICE T operator()(const T& val) const { return acos(val); }
+};
+
+template <>
+struct Acos<platform::float16> {
+  HOSTDEVICE platform::float16 operator()(const platform::float16& val) const {
+    return platform::float16(acos(static_cast<float>(val)));
+  }
+};
+
+// Acos(x) = acos(x)
+template <typename T>
+struct AcosFunctor : public BaseActivationFunctor<T> {
+  template <typename Device, typename X, typename Out>
+  void operator()(Device d, X x, Out out) const {
+    out.device(d) = x.unaryExpr(Acos<T>());
+  }
+};
+
+// acos'(x) = -1/sqrt(1-x^2)
+template <typename T>
+struct AcosGradFunctor : public BaseActivationFunctor<T> {
+  template <typename Device, typename X, typename Out, typename dOut,
+            typename dX>
+  void operator()(Device d, X x, Out out, dOut dout, dX dx) const {
+    dx.device(d) =
+        -dout * static_cast<T>(1) / (static_cast<T>(1) - x.square()).sqrt();
+  }
+};
+
+template <typename T>
+struct Asin {
+  HOSTDEVICE T operator()(const T& val) const { return asin(val); }
+};
+
+template <>
+struct Asin<platform::float16> {
+  HOSTDEVICE platform::float16 operator()(const platform::float16& val) const {
+    return platform::float16(asin(static_cast<float>(val)));
+  }
+};
+
+// Asin(x) = asin(x)
+template <typename T>
+struct AsinFunctor : public BaseActivationFunctor<T> {
+  template <typename Device, typename X, typename Out>
+  void operator()(Device d, X x, Out out) const {
+    out.device(d) = x.unaryExpr(Asin<T>());
+  }
+};
+
+// asin'(x) = 1/sqrt(1-x^2)
+template <typename T>
+struct AsinGradFunctor : public BaseActivationFunctor<T> {
+  template <typename Device, typename X, typename Out, typename dOut,
+            typename dX>
+  void operator()(Device d, X x, Out out, dOut dout, dX dx) const {
+    dx.device(d) =
+        dout * static_cast<T>(1) / (static_cast<T>(1) - x.square()).sqrt();
+  }
+};
+
+template <typename T>
+struct Atan {
+  HOSTDEVICE T operator()(const T& val) const { return atan(val); }
+};
+
+template <>
+struct Atan<platform::float16> {
+  HOSTDEVICE platform::float16 operator()(const platform::float16& val) const {
+    return platform::float16(atan(static_cast<float>(val)));
+  }
+};
+
+// Atan(x) = atan(x)
+template <typename T>
+struct AtanFunctor : public BaseActivationFunctor<T> {
+  template <typename Device, typename X, typename Out>
+  void operator()(Device d, X x, Out out) const {
+    out.device(d) = x.unaryExpr(Atan<T>());
+  }
+};
+
+// atan'(x) =  1 / (1 + x^2)
+template <typename T>
+struct AtanGradFunctor : public BaseActivationFunctor<T> {
+  template <typename Device, typename X, typename Out, typename dOut,
+            typename dX>
+  void operator()(Device d, X x, Out out, dOut dout, dX dx) const {
+    dx.device(d) = dout * static_cast<T>(1) / (static_cast<T>(1) + x.square());
+  }
+};
+
 // round(x) = [x]
 template <typename T>
 struct RoundFunctor : public BaseActivationFunctor<T> {
@@ -1001,13 +1095,16 @@ struct SwishGradFunctor : public BaseActivationFunctor<T> {
   __macro(relu, ReluFunctor, ReluGradFunctor);                       \
   __macro(gelu, GeluFunctor, GeluGradFunctor);                       \
   __macro(tanh, TanhFunctor, TanhGradFunctor);                       \
+  __macro(atan, AtanFunctor, AtanGradFunctor);                       \
   __macro(softshrink, SoftShrinkFunctor, SoftShrinkGradFunctor);     \
   __macro(sqrt, SqrtFunctor, SqrtGradFunctor);                       \
   __macro(abs, AbsFunctor, AbsGradFunctor);                          \
   __macro(ceil, CeilFunctor, ZeroGradFunctor);                       \
   __macro(floor, FloorFunctor, ZeroGradFunctor);                     \
   __macro(cos, CosFunctor, CosGradFunctor);                          \
+  __macro(acos, AcosFunctor, AcosGradFunctor);                       \
   __macro(sin, SinFunctor, SinGradFunctor);                          \
+  __macro(asin, AsinFunctor, AsinGradFunctor);                       \
   __macro(round, RoundFunctor, ZeroGradFunctor);                     \
   __macro(reciprocal, ReciprocalFunctor, ReciprocalGradFunctor);     \
   __macro(log, LogFunctor, LogGradFunctor);                          \

python/paddle/fluid/layers/ops.py

@@ -23,6 +23,7 @@ __activations_noattr__ = [
     'logsigmoid',
     'exp',
     'tanh',
+    'atan',
     'tanh_shrink',
     'softshrink',
     'sqrt',
@@ -30,6 +31,8 @@ __activations_noattr__ = [
     'ceil',
     'floor',
     'cos',
+    'acos',
+    'asin',
     'sin',
     'round',
     'reciprocal',

python/paddle/fluid/tests/unittests/test_activation_op.py

@@ -100,6 +100,23 @@ class TestTanh(TestActivation):
         self.check_grad(['X'], 'Out', max_relative_error=0.007)
 
 
+class TestAtan(TestActivation):
+    def setUp(self):
+        self.op_type = "atan"
+        self.init_dtype()
+
+        x = np.random.uniform(0.1, 1, [11, 17]).astype(self.dtype)
+        out = np.arctan(x)
+
+        self.inputs = {'X': OpTest.np_dtype_to_fluid_dtype(x)}
+        self.outputs = {'Out': out}
+
+    def test_check_grad(self):
+        if self.dtype == np.float16:
+            return
+        self.check_grad(['X'], 'Out', max_relative_error=0.007)
+
+
 class TestTanhShrink(TestActivation):
     def setUp(self):
         self.op_type = "tanh_shrink"
@@ -248,6 +265,23 @@ class TestCos(TestActivation):
         self.check_grad(['X'], 'Out', max_relative_error=0.007)
 
 
+class TestAcos(TestActivation):
+    def setUp(self):
+        self.op_type = "acos"
+        self.init_dtype()
+
+        x = np.random.uniform(-1, 1, [4, 4]).astype(self.dtype)
+        out = np.arccos(x)
+
+        self.inputs = {'X': OpTest.np_dtype_to_fluid_dtype(x)}
+        self.outputs = {'Out': out}
+
+    def test_check_grad(self):
+        if self.dtype == np.float16:
+            return
+        self.check_grad(['X'], 'Out', max_relative_error=0.007)
+
+
 class TestSin(TestActivation):
     def setUp(self):
         self.op_type = "sin"
@@ -265,6 +299,23 @@ class TestSin(TestActivation):
         self.check_grad(['X'], 'Out', max_relative_error=0.007)
 
 
+class TestAsin(TestActivation):
+    def setUp(self):
+        self.op_type = "asin"
+        self.init_dtype()
+
+        x = np.random.uniform(-1, 1, [4, 4]).astype(self.dtype)
+        out = np.arcsin(x)
+
+        self.inputs = {'X': OpTest.np_dtype_to_fluid_dtype(x)}
+        self.outputs = {'Out': out}
+
+    def test_check_grad(self):
+        if self.dtype == np.float16:
+            return
+        self.check_grad(['X'], 'Out', max_relative_error=0.007)
+
+
 class TestRound(TestActivation):
     def setUp(self):
         self.op_type = "round"
@@ -665,7 +716,10 @@ create_test_act_fp16_class(TestAbs)
 create_test_act_fp16_class(TestCeil, grad_check=False)
 create_test_act_fp16_class(TestFloor, grad_check=False)
 create_test_act_fp16_class(TestCos, grad_atol=0.85)
+create_test_act_fp16_class(TestAcos, grad_atol=0.85)
 create_test_act_fp16_class(TestSin)
+create_test_act_fp16_class(TestAsin)
+create_test_act_fp16_class(TestAtan)
 create_test_act_fp16_class(TestRound, grad_check=False)
 create_test_act_fp16_class(TestRelu)
 create_test_act_fp16_class(TestGelu)