| | |
| | | if (strcmp(s, "sigmoid")==0) return SIGMOID; |
| | | if (strcmp(s, "relu")==0) return RELU; |
| | | if (strcmp(s, "identity")==0) return IDENTITY; |
| | | if (strcmp(s, "ramp")==0) return RAMP; |
| | | fprintf(stderr, "Couldn't find activation function %s, going with ReLU\n", s); |
| | | return RELU; |
| | | } |
| | | |
| | | double activate(double x, ACTIVATION a){ |
| | | switch(a){ |
| | | case IDENTITY: |
| | | return x; |
| | | case SIGMOID: |
| | | return 1./(1.+exp(-x)); |
| | | case RELU: |
| | | return x*(x>0); |
| | | case RAMP: |
| | | return x*(x>0) + .1*x; |
| | | } |
| | | return 0; |
| | | } |
| | | double gradient(double x, ACTIVATION a){ |
| | | switch(a){ |
| | | case IDENTITY: |
| | | return 1; |
| | | case SIGMOID: |
| | | return (1.-x)*x; |
| | | case RELU: |
| | | return (x>0); |
| | | case RAMP: |
| | | return (x>0) + .1; |
| | | } |
| | | return 0; |
| | | } |
| | | |
| | | double identity_activation(double x) |
| | | { |
| | | return x; |
| | |
| | | } |
| | | double relu_gradient(double x) |
| | | { |
| | | return (x>=0); |
| | | return (x>0); |
| | | } |
| | | |
| | | double sigmoid_activation(double x) |