[fix] modify activation function

.vscode/settings.json

@@ -1,6 +1,8 @@
 {
     "files.associations": {
         "iosfwd": "cpp",
-        "vector": "cpp"
+        "vector": "cpp",
+        "iostream": "cpp",
+        "ostream": "cpp"
     }
 }

.vscode/tasks.json

@@ -0,0 +1,28 @@
+{
+    "tasks": [
+        {
+            "type": "cppbuild",
+            "label": "C/C++: g++ build active file",
+            "command": "/usr/bin/g++",
+            "args": [
+                "-fdiagnostics-color=always",
+                "-g",
+                "${file}",
+                "-o",
+                "${fileDirname}/${fileBasenameNoExtension}"
+            ],
+            "options": {
+                "cwd": "${fileDirname}"
+            },
+            "problemMatcher": [
+                "$gcc"
+            ],
+            "group": {
+                "kind": "build",
+                "isDefault": true
+            },
+            "detail": "Task generated by Debugger."
+        }
+    ],
+    "version": "2.0.0"
+}

CMakeLists.txt

@@ -1,18 +1,30 @@
 cmake_minimum_required(VERSION 3.10)
 project(InfernoML)
 
+# Set C++ standard
 set(CMAKE_CXX_STANDARD 11)
+set(CMAKE_CXX_STANDARD_REQUIRED True)
 
 # Include directories
 include_directories(include)
 
-# Source files
+# Define libraries
 add_library(InfernoML STATIC
     src/algorithms/linear_regression.cpp
 )
 
-# Example executable
+add_library(Activations STATIC
+    src/activation/activation_functions.cpp
+)
+
+# Define executables
 add_executable(linear_regression_example examples/linear_regression_example.cpp)
-target_link_libraries(linear_regression_example PRIVATE InfernoML)
+add_executable(activation_functions_example examples/activation_functions_example.cpp)
 
+# Link libraries to executables
+target_link_libraries(linear_regression_example PRIVATE InfernoML)
+target_link_libraries(activation_functions_example PRIVATE Activations)
 
+# Ensure that include directories are added for the specific targets if necessary
+target_include_directories(linear_regression_example PRIVATE ${PROJECT_SOURCE_DIR}/include)
+target_include_directories(activation_functions_example PRIVATE ${PROJECT_SOURCE_DIR}/include)

examples/activation_functions_example.cpp

@@ -0,0 +1,29 @@
+#include <iostream>
+#include <vector>
+#include "activation/activation_functions.h"  // Include your header file
+
+int main() {
+    // Define input vector
+    std::vector<double> inputs = {0.5, -0.3, 0.8, -1.2, 0.0};
+
+    // Apply sigmoid function to the inputs
+    std::vector<double> sigmoid_results = activation::ActivationFunctions::apply(inputs, activation::ActivationFunctions::sigmoid);
+
+    // Apply ReLU function to the inputs
+    std::vector<double> relu_results = activation::ActivationFunctions::apply(inputs, activation::ActivationFunctions::relu);
+
+    // Print results
+    std::cout << "Sigmoid Results:" << std::endl;
+    for (double result : sigmoid_results) {
+        std::cout << result << " ";
+    }
+    std::cout << std::endl;
+
+    std::cout << "ReLU Results:" << std::endl;
+    for (double result : relu_results) {
+        std::cout << result << " ";
+    }
+    std::cout << std::endl;
+
+    return 0;
+}

include/activation/activation_functions.h

@@ -2,31 +2,23 @@
 #define ACTIVATION_FUNCTIONS_H
 
 #include <vector>
-#include <cmath>
 
 namespace activation {
 
-    // Sigmoid activation function
-    inline double sigmoid(double x);
-
-    // Derivative of sigmoid function
-    inline double sigmoid_derivative(double x);
-
-    // Tanh activation function
-    inline double tanh(double x);
-
-    // Derivative of tanh function
-    inline double tanh_derivative(double x);
-
-    // ReLU activation function
-    inline double relu(double x);
-
-    // Derivative of ReLU function
-    inline double relu_derivative(double x);
-
-    // Apply an activation function to a vector
-    template <typename Func>
-    std::vector<double> apply(const std::vector<double>& inputs, Func func);
+    class ActivationFunctions {
+    public:
+        // Activation functions
+        static double sigmoid(double x);
+        static double sigmoid_derivative(double x);
+        static double tanh(double x);
+        static double tanh_derivative(double x);
+        static double relu(double x);
+        static double relu_derivative(double x);
+
+        // Apply an activation function to a vector
+        template <typename Func>
+        static std::vector<double> apply(const std::vector<double>& inputs, Func func);
+    };
 
 } // namespace activation
 

src/activation/activation_functions.cpp

@@ -1,51 +1,48 @@
 #include "activation/activation_functions.h"
+#include <cmath>
+#include <algorithm>
 
 namespace activation {
 
-// Sigmoid activation function
-inline double sigmoid(double x) {
-    return 1.0 / (1.0 + std::exp(-x));
-}
-
-// Derivative of sigmoid function
-inline double sigmoid_derivative(double x) {
-    double sig = sigmoid(x);
-    return sig * (1.0 - sig);
-}
-
-// Tanh activation function
-inline double tanh(double x) {
-    return std::tanh(x);
-}
-
-// Derivative of tanh function
-inline double tanh_derivative(double x) {
-    double tanh_x = tanh(x);
-    return 1.0 - tanh_x * tanh_x;
-}
-
-// ReLU activation function
-inline double relu(double x) {
-    return std::max(0.0, x);
-}
-
-// Derivative of ReLU function
-inline double relu_derivative(double x) {
-    return (x > 0) ? 1.0 : 0.0;
-}
-
-// Apply an activation function to a vector
-template <typename Func>
-std::vector<double> apply(const std::vector<double>& inputs, Func func) {
-    std::vector<double> result;
-    result.reserve(inputs.size());
-    for (double input : inputs) {
-        result.push_back(func(input));
+    // Activation functions
+    double ActivationFunctions::sigmoid(double x) {
+        return 1.0 / (1.0 + std::exp(-x));
     }
-    return result;
-}
 
-// Explicit template instantiations
-template std::vector<double> apply(const std::vector<double>& inputs, double (*func)(double));
+    double ActivationFunctions::sigmoid_derivative(double x) {
+        double sig = sigmoid(x);
+        return sig * (1.0 - sig);
+    }
+
+    double ActivationFunctions::tanh(double x) {
+        return std::tanh(x);
+    }
+
+    double ActivationFunctions::tanh_derivative(double x) {
+        double tanh_x = tanh(x);
+        return 1.0 - tanh_x * tanh_x;
+    }
+
+    double ActivationFunctions::relu(double x) {
+        return std::max(0.0, x);
+    }
+
+    double ActivationFunctions::relu_derivative(double x) {
+        return (x > 0) ? 1.0 : 0.0;
+    }
+
+    // Apply an activation function to a vector
+    template <typename Func>
+    std::vector<double> ActivationFunctions::apply(const std::vector<double>& inputs, Func func) {
+        std::vector<double> result;
+        result.reserve(inputs.size());
+        for (double input : inputs) {
+            result.push_back(func(input));
+        }
+        return result;
+    }
+
+    // Explicit template instantiation
+    template std::vector<double> ActivationFunctions::apply(const std::vector<double>&, double (*)(double));
 
 } // namespace activation