modified pattern

Author: CVH95

CMakeLists.txt

@@ -46,5 +46,11 @@ target_link_libraries(test_psn transfer_function neuron so2_cpg psn)
 add_executable(test_vrn tests/test_vrn.cpp)
 target_link_libraries(test_vrn transfer_function neuron so2_cpg psn vrn)
 
+add_executable(test_sine_rectification tests/test_sine_rectification.cpp)
+target_link_libraries(test_sine_rectification transfer_function)
+
+add_executable(test_so2_rectification tests/test_so2_rectification.cpp)
+target_link_libraries(test_so2_rectification transfer_function neuron so2_cpg)
+
 # Output end message
 MESSAGE(${PROJECT_NAME} " done!")

SO2/include/so2_cpg.h

@@ -42,6 +42,7 @@ class so2{
         vector<float> timeSpace(float t0, float tf, int sample);
         tuple<float, float, float> intraLegCoordination(float ti, vector<float> weights, vector<float> biases, float hz, float o1, float o2);
         vector<float> get_output();
+        float threshold_so2_signal(float oi, float oi_prev);
         void udpate_output(float x, float y);
 
     private:

SO2/src/so2_cpg.cpp

@@ -72,6 +72,33 @@ vector<float> so2::get_output()
     return output;
 }
 
+// Threshold SO2 signal (dung beetle)
+float so2::threshold_so2_signal(float oi, float oi_prev)
+{
+    float _oi;
+    // First threshold, on y(x)
+    if(oi >= 0.0)
+    {
+        // Approximating derivative
+        float diff = oi - oi_prev;
+        // Second threshold, on y'(x)
+        if(diff >= 0.0)
+        {
+            _oi = oi;
+        }
+        else
+        {       
+            _oi = 0;
+        }
+    }
+    else
+    {
+        _oi = 0;
+    }
+
+    return _oi;
+}
+
 // Update output value (positional)
 void so2::udpate_output(float x, float y)
 {

TransferFunction/include/transfer_function.h

@@ -25,13 +25,20 @@ class transfer_function{
     public:
 
         // Functions
+        float cosine(float amp, float f, float x);
         float gaussian(float x, float std);
         float linear(float x);
         float linear_biased(float x, float m, float n);
         float sigmoid(float x);
+        float sine(float amp, float f, float rad);
         float step_threshold(float x, float threshold);
         float tanh(float x);
-        
+        tuple<float, float> thresholded_sine(float amp, float f, float rad, float z_prev);
+    
+    private:
+
+        // For approximating the derivative
+        float resolution = 0.001;
 };
 
 #endif /* TRANSFER_FUNCTION_H_ */

TransferFunction/src/transfer_function.cpp

@@ -1,5 +1,12 @@
 #include <transfer_function.h>
 
+// Cosine function (x must be in radians)
+float transfer_function::cosine(float amp, float f, float rad)
+{
+    float w = 2*PI*f;
+    float y = amp*cos(w*rad);
+    return y;
+}
 
 // Gaussian transfer function
 float transfer_function::gaussian(float x, float std)
@@ -31,6 +38,14 @@ float transfer_function::sigmoid(float x)
     return y;
 }
 
+// Sine function (x must be in radians)
+float transfer_function::sine(float amp, float f, float rad)
+{
+    float w = 2*PI*f;
+    float y = amp*sin(w*rad);
+    return y;
+}
+
 // Step function
 float transfer_function::step_threshold(float x, float threshold)
 {
@@ -53,4 +68,31 @@ float transfer_function::tanh(float x)
 {
     float y = ((2.0/ (1.0 + exp(-2.0 * x))) - 1.0);
     return y;
+}
+
+// Thresholded sine
+tuple<float, float> transfer_function::thresholded_sine(float amp, float f, float rad, float z_prev)
+{
+    float w = 2*PI*f;
+    float y;
+    float z = amp*sin(w*rad);
+    // First threshold, on F(x)
+    if(z >= 0.0)
+    {
+        // Second threshold, on F'(x)
+        float diff = z - z_prev;
+        if(diff >= 0.0)
+        {
+            y = z;
+        }
+        else
+        {
+            y = 0;
+        }
+    }
+    else
+    {
+        y = 0.0;
+    }
+    return make_tuple(y, z);
 }