Adding crossover function

lib/matrix.js

@@ -18,6 +18,17 @@ class Matrix {
     return m;
   }
 
+  static crossover(a, b, ratio = 0.5) {
+    if (!a instanceof this || !b instanceof this || a.rows !== b.rows || a.cols !== b.cols) {
+      console.log('Columns and Rows of A must match Columns and Rows of B.');
+      return;
+    }
+
+    let m = a.copy();
+    m.map((value, i, j) => Math.random() < ratio ? value : b.data[i][j]);
+    return m;
+  }
+
   static fromArray(arr) {
     return new Matrix(arr.length, 1).map((e, i) => arr[i]);
   }

lib/nn.js

@@ -175,6 +175,19 @@ class NeuralNetwork {
     this.bias_o.map(mutate);
   }
 
+  static crossover(a, b, ratio = 0.5) {
+    if (!a instanceof this || !b instanceof this || a.input_nodes !== b.input_nodes || a.hidden_nodes !== b.hidden_nodes || a.output_nodes !== b.output_nodes) {
+      console.error('Only NeuralNetworks of the same breed can generate offspring.');
+      return;
+    }
+
+    let nn = a.copy();
+    nn.weights_ih = Matrix.crossover(a.weights_ih, b.weights_ih, ratio);
+    nn.weights_ho = Matrix.crossover(a.weights_ho, b.weights_ho, ratio);
+    nn.bias_h = Matrix.crossover(a.bias_h, b.bias_h, ratio);
+    nn.bias_o = Matrix.crossover(a.bias_o, b.bias_o, ratio);
+    return nn;
+  }
 
 
 }