Saving and Loading a Neural Network

The ModelSerializer is a 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.

Model serializer

ModelSerializer

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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 updateror 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 streamNote: 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 streamNote: 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 restoredusing {- 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