2 files changed, 88 insertions, 1 deletions

diff --git a/src/nn.c b/src/nn.c
index 1f70785..1d08c6b 100644
--- a/src/nn.c
+++ b/src/nn.c
@@ -1,6 +1,8 @@
 #include "nn.h"
 
 static void fill_random_weights(double *weights, double *bias, size_t rows, size_t cols);
+static double get_avg_loss(double labels[], double outs[], size_t shape[2], double (*loss)(double, double));
+
 
 double relu(double x);
 double drelu(double x);
@@ -17,6 +19,63 @@ struct Activation NN_SIGMOID = {
     .dfunc = dsigmoid
 };
 
+
+void nn_network_train(
+        Layer network[], size_t network_size,
+        double *input, size_t input_shape[2],
+        double *labels, size_t labels_shape[2],
+        struct Cost cost, size_t epochs, double alpha)
+{
+    assert(input_shape[0] == labels_shape[0] && "label samples don't correspond with input samples\n");
+
+    double **outs = calloc(network_size, sizeof(double *));
+    double **zouts = calloc(network_size, sizeof(double *));
+    double **weights = calloc(network_size, sizeof(double *));
+    double **biases = calloc(network_size, sizeof(double *));
+
+    if (!outs || !zouts || !weights || !biases) goto nn_network_train_error;
+
+
+
+    size_t samples = input_shape[0];
+    for (size_t l = 0; l < network_size; l++) {
+        outs[l] = calloc(samples * network[l].neurons, sizeof(double));
+        zouts[l] = calloc(samples * network[l].neurons, sizeof(double));
+        weights[l] = calloc(network[l].input_nodes * network[l].neurons, sizeof(double));
+        biases[l] = calloc(network[l].neurons, sizeof(double));
+    }
+
+    for (size_t epoch = 0; epoch < epochs; epochs++) {
+        nn_forward(outs, zouts, input, input_shape, network, network_size);
+        nn_backward(
+                weights, biases,
+                zouts, outs,
+                input, input_shape,
+                labels, labels_shape,
+                network, network_size,
+                cost.dfunc_out, alpha);
+        double *net_out = outs[network_size - 1];
+        fprintf(stderr, "epoch: %zu \tavg loss: %6.2lf\n",
+                epoch, get_avg_loss(labels, net_out, labels_shape, cost.func));
+    }
+
+    for (size_t l = 0; l < network_size; l++) {
+        free(outs[l]);
+        free(zouts[l]);
+        free(weights[l]);
+        free(biases[l]);
+    }
+
+    free(zouts);
+    free(outs);
+    free(weights);
+    free(biases);
+
+nn_network_train_error:
+    perror("nn_network_train() Error");
+    exit(1);
+}
+
 void nn_backward(
         double **weights, double **bias,
         double **Zout, double **Outs,
@@ -65,7 +124,12 @@ void nn_backward(
                 nn_layer_hidden_delta(delta, delta_next, zout, weights[l+1], weigths_next_shape, network[l].activation.dfunc);
                 nn_layer_backward(weights[l], bias[l], weigths_shape, delta, out_prev, network[l], alpha);
             }
-            memcpy(delta_next, delta, weigths_shape[1] * sizeof(double));
+            memmove(delta_next, delta, weigths_shape[1] * sizeof(double));
+        }
+        for (size_t l = network_size - 1; l >= 0; l--) {
+            size_t weigths_shape[2] = {network[l].input_nodes, network[l].neurons};
+            memmove(network[l].weights, weights[l], weigths_shape[0] * weigths_shape[1] * sizeof(double));
+            memmove(network[l].bias, bias[l], weigths_shape[1] * sizeof(double));
         }
     }
 
@@ -266,3 +330,15 @@ double relu(double x)
 double drelu(double x) {
     return (x > 0) ? 1 : 0;
 }
+
+double get_avg_loss(double labels[], double outs[], size_t shape[2], double (*loss)(double, double))
+{
+    double sum = 0;
+    for (size_t i = 0; i < shape[0]; i++) {
+        for (size_t j = 0; j < shape[1]; j++) {
+            size_t index = i * shape[1] + j;
+            sum += loss(labels[index], outs[index]);
+        }
+    }
+    return sum / shape[1];
+}
diff --git a/src/nn.h b/src/nn.h
index 0c794b5..40066e3 100644
--- a/src/nn.h
+++ b/src/nn.h
@@ -10,6 +10,11 @@
 #include <unistd.h>
 #include <openblas/cblas.h>
 
+struct Cost {
+    double (*func)(double labels, double net_out);
+    double (*dfunc_out)(double labels, double net_out);
+};
+
 struct Activation {
     double (*func)(double);
     double (*dfunc)(double);
@@ -24,6 +29,12 @@ typedef struct Layer {
 void nn_network_init_weights(Layer *network, size_t nmemb, size_t input_cols);
 void nn_network_free_weights(Layer *network, size_t nmemb);
 
+void nn_network_train(
+        Layer network[], size_t network_size,
+        double *input, size_t input_shape[2],
+        double *labels, size_t labels_shape[2],
+        struct Cost cost, size_t epochs, double alpha);
+
 void nn_layer_map_activation(
         double (*activation)(double),
         double *aout, size_t aout_shape[2],