export function updateWeights()

in src/nn.ts [335:376]

• 41 lines of code
• 10 McCabe index (conditional complexity)

export function updateWeights(network: Node[][], learningRate: number,
    regularizationRate: number) {
  for (let layerIdx = 1; layerIdx < network.length; layerIdx++) {
    let currentLayer = network[layerIdx];
    for (let i = 0; i < currentLayer.length; i++) {
      let node = currentLayer[i];
      // Update the node's bias.
      if (node.numAccumulatedDers > 0) {
        node.bias -= learningRate * node.accInputDer / node.numAccumulatedDers;
        node.accInputDer = 0;
        node.numAccumulatedDers = 0;
      }
      // Update the weights coming into this node.
      for (let j = 0; j < node.inputLinks.length; j++) {
        let link = node.inputLinks[j];
        if (link.isDead) {
          continue;
        }
        let regulDer = link.regularization ?
            link.regularization.der(link.weight) : 0;
        if (link.numAccumulatedDers > 0) {
          // Update the weight based on dE/dw.
          link.weight = link.weight -
              (learningRate / link.numAccumulatedDers) * link.accErrorDer;
          // Further update the weight based on regularization.
          let newLinkWeight = link.weight -
              (learningRate * regularizationRate) * regulDer;
          if (link.regularization === RegularizationFunction.L1 &&
              link.weight * newLinkWeight < 0) {
            // The weight crossed 0 due to the regularization term. Set it to 0.
            link.weight = 0;
            link.isDead = true;
          } else {
            link.weight = newLinkWeight;
          }
          link.accErrorDer = 0;
          link.numAccumulatedDers = 0;
        }
      }
    }
  }
}