fix bug

This reverts commit 6ba9ba3195.

matrix.c

@@ -67,14 +67,18 @@ Matrix add(const Matrix matrix1, const Matrix matrix2)
         return createMatrix(0, 0);
     }
 
+    // matrices not compatible
+    if (matrix1.rows != matrix2.rows)
+    {
+        clearMatrix(&resMat);
+        return resMat;
+    }
+
+    // check if broadcasting is possible
     if (matrix1.cols != matrix2.cols)
     {
-        if (matrix1.rows != matrix2.rows)
-        {
-            clearMatrix(&resMat);
-            return resMat;
-        }
-        else if (matrix1.cols == 1)
+        // matrix1 is a vector
+        if (matrix1.cols == 1)
         {
             // broadcast vector
             for (size_t m = 0; m < matrix2.rows; m++)
@@ -86,6 +90,7 @@ Matrix add(const Matrix matrix1, const Matrix matrix2)
             }
             return resMat;
         }
+        // matrix2 is a vector
         else if (matrix2.cols == 1)
         {
             // broadcast vector
@@ -98,6 +103,7 @@ Matrix add(const Matrix matrix1, const Matrix matrix2)
             }
             return resMat;
         }
+        // addition not possible
         else
         {
             clearMatrix(&resMat);

neuralNetworkTests.c

@@ -5,10 +5,46 @@
 #include "unity.h"
 #include "neuralNetwork.h"
 
+static void writeLayer(FILE *file, const Matrix weights, const Matrix biases, unsigned int inputDim)
+{
+    unsigned int outputDim = (unsigned int)weights.rows;
+    fwrite(&outputDim, sizeof(unsigned int), 1, file);
+    if (weights.buffer != NULL)
+        fwrite(weights.buffer, sizeof(MatrixType), outputDim * inputDim, file);
+
+    if (biases.buffer != NULL)
+        fwrite(biases.buffer, sizeof(MatrixType), outputDim, file);
+}
+
 
 static void prepareNeuralNetworkFile(const char *path, const NeuralNetwork nn)
 {
-    // TODO
+    FILE *file = fopen(path, "wb");
+    if (!file) return;
+
+    const char tag[] = "__info2_neural_network_file_format__";
+    fwrite(tag, sizeof(char), strlen(tag), file);
+
+    if (nn.numberOfLayers == 0)
+    {
+        unsigned int zero = 0;
+        fwrite(&zero, sizeof(unsigned int), 1, file);
+        fclose(file);
+        return;
+    }
+
+    unsigned int inputDim = (unsigned int)nn.layers[0].weights.cols;
+    fwrite(&inputDim, sizeof(unsigned int), 1, file);
+
+    for (int i = 0; i < nn.numberOfLayers; i++)
+    {
+        writeLayer(file, nn.layers[i].weights, nn.layers[i].biases, inputDim);
+        inputDim = (unsigned int)nn.layers[i].weights.rows;
+    }
+    unsigned int zero = 0;
+    fwrite(&zero, sizeof(unsigned int), 1, file);
+
+    fclose(file);
 }
 
 void test_loadModelReturnsCorrectNumberOfLayers(void)