Model Persistence

Saving and loading of neural networks.

MultiLayerNetwork and ComputationGraph both have save and load methods.

You can save/load a MultiLayerNetwork using:

MultiLayerNetwork net = ...
net.save(new File("...");
MultiLayerNetwork net2 = MultiLayerNetwork.load(new File("..."), true);

Similarly, you can save/load a ComputationGraph using:

ComputationGraph net = ...
net.save(new File("..."));
ComputationGraph net2 = ComputationGraph.load(new File("..."), true);

Internally, these methods use the ModelSerializer class, which handles loading and saving models. There are two methods for saving models shown in the examples through the link. The first example saves a normal multilayer network, the second one saves a computation graph.

Here is a basic example with code to save a computation graph using the ModelSerializer class, as well as an example of using ModelSerializer to save a neural net built using MultiLayer configuration.

RNG Seed

If your model uses probabilities (i.e. DropOut/DropConnect), it may make sense to save it separately, and apply it after model is restored; i.e:

Nd4j.getRandom().setSeed(12345);
ModelSerializer.restoreMultiLayerNetwork(modelFile);

This will guarantee equal results between sessions/JVMs.

ModelSerializer

[source]

Utility class suited to save/restore neural net models

writeModel

public static void writeModel(@NonNull Model model, @NonNull File file, boolean saveUpdater) throws IOException

Write a model to a file

  • param model the model to write

  • param file the file to write to

  • param saveUpdater whether to save the updater or not

  • throws IOException

writeModel

public static void writeModel(@NonNull Model model, @NonNull File file, boolean saveUpdater,DataNormalization dataNormalization) throws IOException

Write a model to a file

  • param model the model to write

  • param file the file to write to

  • param saveUpdater whether to save the updater or not

  • param dataNormalization the normalizer to save (optional)

  • throws IOException

writeModel

public static void writeModel(@NonNull Model model, @NonNull String path, boolean saveUpdater) throws IOException

Write a model to a file path

  • param model the model to write

  • param path the path to write to

  • param saveUpdater whether to save the updater or not

  • throws IOException

writeModel

public static void writeModel(@NonNull Model model, @NonNull OutputStream stream, boolean saveUpdater)
throws IOException

Write a model to an output stream

  • param model the model to save

  • param stream the output stream to write to

  • param saveUpdater whether to save the updater for the model or not

  • throws IOException

writeModel

public static void writeModel(@NonNull Model model, @NonNull OutputStream stream, boolean saveUpdater,DataNormalization dataNormalization)
throws IOException

Write a model to an output stream

  • param model the model to save

  • param stream the output stream to write to

  • param saveUpdater whether to save the updater for the model or not

  • param dataNormalization the normalizer ot save (may be null)

  • throws IOException

restoreMultiLayerNetwork

public static MultiLayerNetwork restoreMultiLayerNetwork(@NonNull File file) throws IOException

Load a multi layer network from a file

  • param file the file to load from

  • return the loaded multi layer network

  • throws IOException

restoreMultiLayerNetwork

public static MultiLayerNetwork restoreMultiLayerNetwork(@NonNull File file, boolean loadUpdater)
throws IOException

Load a multi layer network from a file

  • param file the file to load from

  • return the loaded multi layer network

  • throws IOException

restoreMultiLayerNetwork

public static MultiLayerNetwork restoreMultiLayerNetwork(@NonNull InputStream is, boolean loadUpdater)
throws IOException

Load a MultiLayerNetwork from InputStream from an input stream Note: the input stream is read fully and closed by this method. Consequently, the input stream cannot be re-used.

  • param is the inputstream to load from

  • return the loaded multi layer network

  • throws IOException

  • see #restoreMultiLayerNetworkAndNormalizer(InputStream, boolean)

restoreMultiLayerNetwork

public static MultiLayerNetwork restoreMultiLayerNetwork(@NonNull InputStream is) throws IOException

Restore a multi layer network from an input stream Note: the input stream is read fully and closed by this method. Consequently, the input stream cannot be re-used.

  • param is the input stream to restore from

  • return the loaded multi layer network

  • throws IOException

  • see #restoreMultiLayerNetworkAndNormalizer(InputStream, boolean)

restoreMultiLayerNetwork

public static MultiLayerNetwork restoreMultiLayerNetwork(@NonNull String path) throws IOException

Load a MultilayerNetwork model from a file

  • param path path to the model file, to get the computation graph from

  • return the loaded computation graph

  • throws IOException

restoreMultiLayerNetwork

public static MultiLayerNetwork restoreMultiLayerNetwork(@NonNull String path, boolean loadUpdater)
throws IOException

Load a MultilayerNetwork model from a file

  • param path path to the model file, to get the computation graph from

  • return the loaded computation graph

  • throws IOException

restoreComputationGraph

public static ComputationGraph restoreComputationGraph(@NonNull String path) throws IOException

Restore a MultiLayerNetwork and Normalizer (if present - null if not) from the InputStream. Note: the input stream is read fully and closed by this method. Consequently, the input stream cannot be re-used.

  • param is Input stream to read from

  • param loadUpdater Whether to load the updater from the model or not

  • return Model and normalizer, if present

  • throws IOException If an error occurs when reading from the stream

restoreComputationGraph

public static ComputationGraph restoreComputationGraph(@NonNull String path, boolean loadUpdater)
throws IOException

Load a computation graph from a file

  • param path path to the model file, to get the computation graph from

  • return the loaded computation graph

  • throws IOException

restoreComputationGraph

public static ComputationGraph restoreComputationGraph(@NonNull InputStream is, boolean loadUpdater)
throws IOException

Load a computation graph from a InputStream

  • param is the inputstream to get the computation graph from

  • return the loaded computation graph

  • throws IOException

restoreComputationGraph

public static ComputationGraph restoreComputationGraph(@NonNull InputStream is) throws IOException

Load a computation graph from a InputStream

  • param is the inputstream to get the computation graph from

  • return the loaded computation graph

  • throws IOException

restoreComputationGraph

public static ComputationGraph restoreComputationGraph(@NonNull File file) throws IOException

Load a computation graph from a file

  • param file the file to get the computation graph from

  • return the loaded computation graph

  • throws IOException

restoreComputationGraph

public static ComputationGraph restoreComputationGraph(@NonNull File file, boolean loadUpdater) throws IOException

Restore a ComputationGraph and Normalizer (if present - null if not) from the InputStream. Note: the input stream is read fully and closed by this method. Consequently, the input stream cannot be re-used.

  • param is Input stream to read from

  • param loadUpdater Whether to load the updater from the model or not

  • return Model and normalizer, if present

  • throws IOException If an error occurs when reading from the stream

taskByModel

public static Task taskByModel(Model model)
  • param model

  • return

addNormalizerToModel

public static void addNormalizerToModel(File f, Normalizer<?> normalizer)

This method appends normalizer to a given persisted model.

PLEASE NOTE: File should be model file saved earlier with ModelSerializer

  • param f

  • param normalizer

addObjectToFile

public static void addObjectToFile(@NonNull File f, @NonNull String key, @NonNull Object o)

Add an object to the (already existing) model file using Java Object Serialization. Objects can be restored using {- link #getObjectFromFile(File, String)}

  • param f File to add the object to

  • param key Key to store the object under

  • param o Object to store using Java object serialization