每层的权重和预测

时间:2019-01-21 16:19:27

标签: neural-network tensorflow.js

我正在尝试创建一个简单的神经网络查看器,如下图所示。我可以得到训练后的权重,但是运行预测后,节点值存储在tensorflow js 层中的什么位置?换句话说,我可以获取线值,但不能获取带圆圈的值。在简单的网络中,它们就像传递给fit方法的x和y一样简单。

enter image description here

1 个答案:

答案 0 :(得分:1)

getWeigths允许检索图层的权重

使用tf.model,可以输出每一层的预测

const input = tf.input({shape: [5]});
        const denseLayer1 = tf.layers.dense({units: 10, activation: 'relu'});
        const denseLayer2 = tf.layers.dense({units: 2, activation: 'softmax'});
        const output1 = denseLayer1.apply(input);
        const output2 = denseLayer2.apply(output1);
        const model = tf.model({inputs: input, outputs: [output1, output2]});
        const [firstLayer, secondLayer] = model.predict(tf.ones([2, 5]));
        
        console.log(denseLayer1.getWeights().length) // 2  W and B for a dense layer
        denseLayer1.getWeights()[1].print()
        console.log(denseLayer2.getWeights().length) // also 2
        // output of each layer WX + B
        firstLayer.print();
        secondLayer.print()
<html>
  <head>
    <!-- Load TensorFlow.js -->
    <script src="https://cdn.jsdelivr.net/npm/@tensorflow/tfjs@0.12.0"> </script>
  </head>

  <body>
  </body>
</html>

一个人也可以使用tf.sequential()

做同样的事情

const model = tf.sequential();

// first layer
model.add(tf.layers.dense({units: 10, inputShape: [4]}));
// second layer
model.add(tf.layers.dense({units: 1}));

// get all the layers of the model
const layers = model.layers
layers[0].getWeights()[0].print()
<html>
  <head>
    <!-- Load TensorFlow.js -->
    <script src="https://cdn.jsdelivr.net/npm/@tensorflow/tfjs@0.12.0"> </script>
  </head>

  <body>
  </body>
</html>

但是对于tf.sequential,使用模型配置中作为参数传递的tf.model,无法像使用output那样获得对每一层的预测