JavaApacheIgnite更新以前训练过的ML模型
我有一个用于训练KNN模型的数据集。稍后,我想用新的训练数据更新模型。我看到的是,更新后的模型只接受新的训练数据,而忽略了以前训练过的数据
Vectorizer vec = new DummyVectorizer<Integer>(1, 2).labeled(0);
DatasetTrainer<KNNClassificationModel, Double> trainer = new KNNClassificationTrainer();
KNNClassificationModel model;
KNNClassificationModel modelUpdated;
Map<Integer, Vector> trainingData = new HashMap<Integer, Vector>();
Map<Integer, Vector> trainingDataNew = new HashMap<Integer, Vector>();
Double[][] data1 = new Double[][] {
{0.136,0.644,0.154},
{0.302,0.634,0.779},
{0.806,0.254,0.211},
{0.241,0.951,0.744},
{0.542,0.893,0.612},
{0.334,0.277,0.486},
{0.616,0.259,0.121},
{0.738,0.585,0.017},
{0.124,0.567,0.358},
{0.934,0.346,0.863}};
Double[][] data2 = new Double[][] {
{0.300,0.236,0.193}};
Double[] observationData = new Double[] { 0.8, 0.7 };
// fill dataset (in cache)
for (int i = 0; i < data1.length; i++)
trainingData.put(i, new DenseVector(data1[i]));
// first training / prediction
model = trainer.fit(trainingData, 1, vec);
System.out.println("First prediction : " + model.predict(new DenseVector(observationData)));
// new training data
for (int i = 0; i < data2.length; i++)
trainingDataNew.put(data1.length + i, new DenseVector(data2[i]));
// second training / prediction
modelUpdated = trainer.update(model, trainingDataNew, 1, vec);
System.out.println("Second prediction: " + modelUpdated.predict(new DenseVector(observationData)));
作为输出,我得到以下结果:
First prediction : 0.124
Second prediction: 0.3
这看起来像是第二次预测只使用了数据2,这必须导致0.3作为预测
模型更新是如何工作的?如果我必须将数据2添加到数据1中,然后再次使用数据1进行训练,那么与所有组合数据的全新训练相比,会有什么不同
# 1 楼答案
模型更新是如何工作的?
对于KNN,特别是: 将data2添加到data1,并对组合数据调用modelUpdate
以这个测试为例:https://github.com/apache/ignite/blob/635dafb7742673494efa6e8e91e236820156d38f/modules/ml/src/test/java/org/apache/ignite/ml/knn/KNNClassificationTest.java#L167
按照该测试中的说明进行操作: 设置您的培训师:
然后设置矢量器:(注意标签坐标是如何创建的)
然后根据需要调用updateModel
KNN分类文件:https://ignite.apache.org/docs/latest/machine-learning/binary-classification/knn-classification
KNN分类示例:https://github.com/apache/ignite/blob/master/examples/src/main/java/org/apache/ignite/examples/ml/knn/KNNClassificationExample.java