Add sqrt, exp, round, log functions

fastdeploy/function/math_functor.h

@@ -0,0 +1,56 @@
+// Copyright (c) 2022 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#pragma once
+
+#include "fastdeploy/function/eigen.h"
+
+namespace fastdeploy {
+namespace function {
+
+// log(x) = natural logarithm of x
+template <typename T> struct LogFunctor {
+  template <typename Device, typename X, typename Out>
+  void operator()(Device d, X x, Out out) const {
+    out.device(d) = x.log();
+  }
+};
+
+// exp functor
+// exp(x) = e^x
+template <typename T> struct ExpFunctor {
+  template <typename Device, typename X, typename Out>
+  void operator()(Device d, X x, Out out) const {
+    out.device(d) = x.exp();
+  }
+};
+
+// round(x) = [x]
+template <typename T> struct RoundFunctor {
+  template <typename Device, typename X, typename Out>
+  void operator()(Device d, X x, Out out) const {
+    out.device(d) = x.round();
+  }
+};
+
+// sqrt(x) = x^(1/2)
+template <typename T> struct SqrtFunctor {
+  template <typename Device, typename X, typename Out>
+  void operator()(Device d, X x, Out out) const {
+    out.device(d) = x.sqrt();
+  }
+};
+
+}  // namespace function
+}  // namespace fastdeploy