SHOGUN
4.1.0
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A Deep Belief Network.
A Deep Belief Network [Hinton, 2006] is a multilayer probabilistic generative models. It consists of hidden layers and visible layers. The top hidden layer and the layer below it form a Restricted Boltzmann Machine. The rest of connections in the network are directed connections that go from a hidden layer into a visible layer or another hidden layer.
The network can be pre-trained by treating it as a stack of RBMs. Each hidden layer along with the layer below it form an RBM. Each RBM is then trained using (persistent) contrastive divergence. Pre-training often provides a good initialization for the network's parameters.
After pre-training, the parameters can be fine-tuned using a variant of the wake-sleep algorithm [Hinton, 2006].
The DBN can be used to initialize the parameters of a neural network using convert_to_neural_network().
Samples can be drawn from the model by starting with a random state for the top hidden layer, performing some steps of Gibbs sampling in the top RBM to obtain the states of the top hidden layer and then using those to infer the states of the lower layers using a down-pass.
Steps for using the DBN class:
Definition at line 91 of file DeepBeliefNetwork.h.
Public Member Functions | |
CDeepBeliefNetwork () | |
CDeepBeliefNetwork (int32_t num_visible_units, ERBMVisibleUnitType unit_type=RBMVUT_BINARY) | |
virtual | ~CDeepBeliefNetwork () |
virtual void | add_hidden_layer (int32_t num_units) |
virtual void | initialize_neural_network (float64_t sigma=0.01) |
virtual void | set_batch_size (int32_t batch_size) |
virtual void | pre_train (CDenseFeatures< float64_t > *features) |
virtual void | pre_train (int32_t index, CDenseFeatures< float64_t > *features) |
virtual void | train (CDenseFeatures< float64_t > *features) |
virtual CDenseFeatures < float64_t > * | transform (CDenseFeatures< float64_t > *features, int32_t i=-1) |
virtual CDenseFeatures < float64_t > * | sample (int32_t num_gibbs_steps=1, int32_t batch_size=1) |
virtual void | reset_chain () |
virtual CNeuralNetwork * | convert_to_neural_network (CNeuralLayer *output_layer=NULL, float64_t sigma=0.01) |
virtual SGMatrix< float64_t > | get_weights (int32_t index, SGVector< float64_t > p=SGVector< float64_t >()) |
virtual SGVector< float64_t > | get_biases (int32_t index, SGVector< float64_t > p=SGVector< float64_t >()) |
virtual const char * | get_name () const |
virtual CSGObject * | shallow_copy () const |
virtual CSGObject * | deep_copy () const |
virtual bool | is_generic (EPrimitiveType *generic) const |
template<class T > | |
void | set_generic () |
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void | set_generic () |
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void | set_generic () |
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void | set_generic () |
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void | set_generic () |
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void | set_generic () |
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void | set_generic () |
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void | set_generic () |
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void | set_generic () |
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void | set_generic () |
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void | set_generic () |
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void | set_generic () |
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void | set_generic () |
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void | set_generic () |
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void | set_generic () |
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void | set_generic () |
void | unset_generic () |
virtual void | print_serializable (const char *prefix="") |
virtual bool | save_serializable (CSerializableFile *file, const char *prefix="") |
virtual bool | load_serializable (CSerializableFile *file, const char *prefix="") |
void | set_global_io (SGIO *io) |
SGIO * | get_global_io () |
void | set_global_parallel (Parallel *parallel) |
Parallel * | get_global_parallel () |
void | set_global_version (Version *version) |
Version * | get_global_version () |
SGStringList< char > | get_modelsel_names () |
void | print_modsel_params () |
char * | get_modsel_param_descr (const char *param_name) |
index_t | get_modsel_param_index (const char *param_name) |
void | build_gradient_parameter_dictionary (CMap< TParameter *, CSGObject * > *dict) |
virtual void | update_parameter_hash () |
virtual bool | parameter_hash_changed () |
virtual bool | equals (CSGObject *other, float64_t accuracy=0.0, bool tolerant=false) |
virtual CSGObject * | clone () |
Public Attributes | |
SGVector< int32_t > | pt_cd_num_steps |
SGVector< bool > | pt_cd_persistent |
SGVector< bool > | pt_cd_sample_visible |
SGVector< float64_t > | pt_l2_coefficient |
SGVector< float64_t > | pt_l1_coefficient |
SGVector< int32_t > | pt_monitoring_interval |
SGVector< int32_t > | pt_monitoring_method |
SGVector< int32_t > | pt_max_num_epochs |
SGVector< int32_t > | pt_gd_mini_batch_size |
SGVector< float64_t > | pt_gd_learning_rate |
SGVector< float64_t > | pt_gd_learning_rate_decay |
SGVector< float64_t > | pt_gd_momentum |
int32_t | cd_num_steps |
int32_t | monitoring_interval |
int32_t | max_num_epochs |
int32_t | gd_mini_batch_size |
float64_t | gd_learning_rate |
float64_t | gd_learning_rate_decay |
float64_t | gd_momentum |
SGIO * | io |
Parallel * | parallel |
Version * | version |
Parameter * | m_parameters |
Parameter * | m_model_selection_parameters |
Parameter * | m_gradient_parameters |
uint32_t | m_hash |
Protected Member Functions | |
virtual void | down_step (int32_t index, SGVector< float64_t > params, SGMatrix< float64_t > input, SGMatrix< float64_t > result, bool sample_states=true) |
virtual void | up_step (int32_t index, SGVector< float64_t > params, SGMatrix< float64_t > input, SGMatrix< float64_t > result, bool sample_states=true) |
virtual void | wake_sleep (SGMatrix< float64_t > data, CRBM *top_rbm, SGMatrixList< float64_t > sleep_states, SGMatrixList< float64_t > wake_states, SGMatrixList< float64_t > psleep_states, SGMatrixList< float64_t > pwake_states, SGVector< float64_t > gen_params, SGVector< float64_t > rec_params, SGVector< float64_t > gen_gradients, SGVector< float64_t > rec_gradients) |
virtual void | load_serializable_pre () throw (ShogunException) |
virtual void | load_serializable_post () throw (ShogunException) |
virtual void | save_serializable_pre () throw (ShogunException) |
virtual void | save_serializable_post () throw (ShogunException) |
Protected Attributes | |
ERBMVisibleUnitType | m_visible_units_type |
int32_t | m_num_layers |
CDynamicArray< int32_t > * | m_layer_sizes |
SGMatrixList< float64_t > | m_states |
int32_t | m_batch_size |
SGVector< float64_t > | m_params |
int32_t | m_num_params |
SGVector< int32_t > | m_bias_index_offsets |
SGVector< int32_t > | m_weights_index_offsets |
float64_t | m_sigma |
default constructor
Definition at line 51 of file DeepBeliefNetwork.cpp.
CDeepBeliefNetwork | ( | int32_t | num_visible_units, |
ERBMVisibleUnitType | unit_type = RBMVUT_BINARY |
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Creates a network with one layer of visible units
num_visible_units | Number of visible units |
unit_type | Type of visible units |
Definition at line 56 of file DeepBeliefNetwork.cpp.
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Definition at line 65 of file DeepBeliefNetwork.cpp.
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Adds a layer of hidden units. The layer is connected to the layer that was added directly before it.
num_units | Number of hidden units |
Definition at line 70 of file DeepBeliefNetwork.cpp.
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Builds a dictionary of all parameters in SGObject as well of those of SGObjects that are parameters of this object. Dictionary maps parameters to the objects that own them.
dict | dictionary of parameters to be built. |
Definition at line 597 of file SGObject.cpp.
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Creates a clone of the current object. This is done via recursively traversing all parameters, which corresponds to a deep copy. Calling equals on the cloned object always returns true although none of the memory of both objects overlaps.
Definition at line 714 of file SGObject.cpp.
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Converts the DBN into a neural network with the same structure and parameters. The visible layer in the DBN is converted into a CNeuralInputLayer object, and the hidden layers are converted into CNeuralLogisticLayer objects. An output layer can also be stacked on top of the last hidden layer
output_layer | An output layer |
sigma | Standard deviation of the gaussian used to initialize the parameters of the output layer |
Definition at line 360 of file DeepBeliefNetwork.cpp.
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A deep copy. All the instance variables will also be copied.
Definition at line 198 of file SGObject.cpp.
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Computes the states of some layer using the states of the layer above it
Definition at line 393 of file DeepBeliefNetwork.cpp.
Recursively compares the current SGObject to another one. Compares all registered numerical parameters, recursion upon complex (SGObject) parameters. Does not compare pointers!
May be overwritten but please do with care! Should not be necessary in most cases.
other | object to compare with |
accuracy | accuracy to use for comparison (optional) |
tolerant | allows linient check on float equality (within accuracy) |
Definition at line 618 of file SGObject.cpp.
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Returns the bias vector of layer i
index | Layer index |
p | If specified, the bias vector is extracted from it instead of m_params |
Definition at line 558 of file DeepBeliefNetwork.cpp.
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Definition at line 498 of file SGObject.cpp.
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Returns description of a given parameter string, if it exists. SG_ERROR otherwise
param_name | name of the parameter |
Definition at line 522 of file SGObject.cpp.
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Returns index of model selection parameter with provided index
param_name | name of model selection parameter |
Definition at line 535 of file SGObject.cpp.
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Returns the name of the SGSerializable instance. It MUST BE the CLASS NAME without the prefixed `C'.
Implements CSGObject.
Definition at line 214 of file DeepBeliefNetwork.h.
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Returns the weights matrix between layer i and i+1
index | Layer index |
p | If specified, the weight matrix is extracted from it instead of m_params |
Definition at line 547 of file DeepBeliefNetwork.cpp.
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Initializes the DBN
sigma | Standard deviation of the gaussian used to initialize the weights |
Definition at line 76 of file DeepBeliefNetwork.cpp.
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If the SGSerializable is a class template then TRUE will be returned and GENERIC is set to the type of the generic.
generic | set to the type of the generic if returning TRUE |
Definition at line 296 of file SGObject.cpp.
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Load this object from file. If it will fail (returning FALSE) then this object will contain inconsistent data and should not be used!
file | where to load from |
prefix | prefix for members |
Definition at line 369 of file SGObject.cpp.
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Can (optionally) be overridden to post-initialize some member variables which are not PARAMETER::ADD'ed. Make sure that at first the overridden method BASE_CLASS::LOAD_SERIALIZABLE_POST is called.
ShogunException | will be thrown if an error occurs. |
Reimplemented in CKernel, CWeightedDegreePositionStringKernel, CList, CAlphabet, CLinearHMM, CGaussianKernel, CInverseMultiQuadricKernel, CCircularKernel, and CExponentialKernel.
Definition at line 426 of file SGObject.cpp.
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protectedvirtualinherited |
Can (optionally) be overridden to pre-initialize some member variables which are not PARAMETER::ADD'ed. Make sure that at first the overridden method BASE_CLASS::LOAD_SERIALIZABLE_PRE is called.
ShogunException | will be thrown if an error occurs. |
Reimplemented in CDynamicArray< T >, CDynamicArray< float64_t >, CDynamicArray< float32_t >, CDynamicArray< int32_t >, CDynamicArray< char >, CDynamicArray< bool >, and CDynamicObjectArray.
Definition at line 421 of file SGObject.cpp.
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Definition at line 262 of file SGObject.cpp.
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Pre-trains the DBN as a stack of RBMs
features | Input features. Should have as many features as the number of visible units in the DBN |
Definition at line 149 of file DeepBeliefNetwork.cpp.
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Pre-trains a single RBM
index | Index of the RBM |
features | Input features. Should have as many features as the total number of visible units in the DBN |
Definition at line 159 of file DeepBeliefNetwork.cpp.
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prints all parameter registered for model selection and their type
Definition at line 474 of file SGObject.cpp.
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prints registered parameters out
prefix | prefix for members |
Definition at line 308 of file SGObject.cpp.
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Resets the state of the markov chain used for sampling
Definition at line 352 of file DeepBeliefNetwork.cpp.
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Draws samples from the marginal distribution of the visible units. The sampling starts from the values DBN's internal state and result of the sampling is stored there too.
num_gibbs_steps | Number of Gibbs sampling steps for the top RBM. |
batch_size | Number of samples to be drawn. A seperate chain is used for each sample |
Definition at line 333 of file DeepBeliefNetwork.cpp.
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Save this object to file.
file | where to save the object; will be closed during returning if PREFIX is an empty string. |
prefix | prefix for members |
Definition at line 314 of file SGObject.cpp.
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Can (optionally) be overridden to post-initialize some member variables which are not PARAMETER::ADD'ed. Make sure that at first the overridden method BASE_CLASS::SAVE_SERIALIZABLE_POST is called.
ShogunException | will be thrown if an error occurs. |
Reimplemented in CKernel.
Definition at line 436 of file SGObject.cpp.
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protectedvirtualinherited |
Can (optionally) be overridden to pre-initialize some member variables which are not PARAMETER::ADD'ed. Make sure that at first the overridden method BASE_CLASS::SAVE_SERIALIZABLE_PRE is called.
ShogunException | will be thrown if an error occurs. |
Reimplemented in CKernel, CDynamicArray< T >, CDynamicArray< float64_t >, CDynamicArray< float32_t >, CDynamicArray< int32_t >, CDynamicArray< char >, CDynamicArray< bool >, and CDynamicObjectArray.
Definition at line 431 of file SGObject.cpp.
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Sets the number of train/test cases the RBM will deal with
batch_size | Batch size |
Definition at line 135 of file DeepBeliefNetwork.cpp.
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Definition at line 41 of file SGObject.cpp.
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Definition at line 46 of file SGObject.cpp.
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Definition at line 51 of file SGObject.cpp.
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Definition at line 56 of file SGObject.cpp.
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Definition at line 61 of file SGObject.cpp.
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Definition at line 66 of file SGObject.cpp.
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Definition at line 71 of file SGObject.cpp.
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Definition at line 76 of file SGObject.cpp.
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Definition at line 81 of file SGObject.cpp.
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Definition at line 86 of file SGObject.cpp.
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Definition at line 91 of file SGObject.cpp.
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Definition at line 96 of file SGObject.cpp.
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Definition at line 101 of file SGObject.cpp.
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Definition at line 106 of file SGObject.cpp.
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Definition at line 111 of file SGObject.cpp.
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set generic type to T
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set the parallel object
parallel | parallel object to use |
Definition at line 241 of file SGObject.cpp.
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set the version object
version | version object to use |
Definition at line 283 of file SGObject.cpp.
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A shallow copy. All the SGObject instance variables will be simply assigned and SG_REF-ed.
Reimplemented in CGaussianKernel.
Definition at line 192 of file SGObject.cpp.
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Trains the DBN using the variant of the wake-sleep algorithm described in [A Fast Learning Algorithm for Deep Belief Nets, Hinton, 2006].
features | Input features. Should have as many features as the total number of visible units in the DBN |
Definition at line 210 of file DeepBeliefNetwork.cpp.
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Applies the DBN as a features transformation
Forward-propagates the input features through the DBN and returns the Mean activations of the \( i^{th} \) hidden layer
features | Input features. Should have as many features as the number of visible units in the DBN |
i | Index of the hidden layer. If -1, the activations of the last hidden layer is returned |
Definition at line 316 of file DeepBeliefNetwork.cpp.
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unset generic type
this has to be called in classes specializing a template class
Definition at line 303 of file SGObject.cpp.
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Computes the states of some layer using the states of the layer below it
Definition at line 443 of file DeepBeliefNetwork.cpp.
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Updates the hash of current parameter combination
Definition at line 248 of file SGObject.cpp.
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Computes the gradients using the wake-sleep algorithm
Definition at line 473 of file DeepBeliefNetwork.cpp.
int32_t cd_num_steps |
Number of Gibbs sampling steps performed before each weight update during wake-sleep training. Default value is 1.
Definition at line 306 of file DeepBeliefNetwork.h.
float64_t gd_learning_rate |
Gradient descent learning rate for wake-sleep training, defualt value 0.1
Definition at line 325 of file DeepBeliefNetwork.h.
float64_t gd_learning_rate_decay |
Gradient descent learning rate decay for wake-sleep training. The learning rate is updated at each iteration i according to: alpha(i)=decay*alpha(i-1) Default value is 1.0 (no decay)
Definition at line 332 of file DeepBeliefNetwork.h.
int32_t gd_mini_batch_size |
Size of the mini-batch used during gradient descent wake-sleep training, If 0 full-batch training is performed Default value is 0
Definition at line 322 of file DeepBeliefNetwork.h.
float64_t gd_momentum |
gradient descent momentum multiplier for wake-sleep training
default value is 0.9
For more details on momentum, see this paper [Sutskever, 2013]
Definition at line 342 of file DeepBeliefNetwork.h.
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io
Definition at line 369 of file SGObject.h.
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Number of train/test cases the network is currently dealing with
Definition at line 358 of file DeepBeliefNetwork.h.
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Index at which the bias of each layer is stored in the parameters vector
Definition at line 367 of file DeepBeliefNetwork.h.
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parameters wrt which we can compute gradients
Definition at line 384 of file SGObject.h.
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Hash of parameter values
Definition at line 387 of file SGObject.h.
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Size of each layer
Definition at line 352 of file DeepBeliefNetwork.h.
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model selection parameters
Definition at line 381 of file SGObject.h.
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Number of layers
Definition at line 349 of file DeepBeliefNetwork.h.
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Number of parameters
Definition at line 364 of file DeepBeliefNetwork.h.
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parameters
Definition at line 378 of file SGObject.h.
Parameters of the network
Definition at line 361 of file DeepBeliefNetwork.h.
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Standard deviation of the gaussian used to initialize the parameters
Definition at line 376 of file DeepBeliefNetwork.h.
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States of each layer
Definition at line 355 of file DeepBeliefNetwork.h.
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Type of the visible units
Definition at line 346 of file DeepBeliefNetwork.h.
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Index at which the weights of each hidden layer is stored in the parameters vector
Definition at line 372 of file DeepBeliefNetwork.h.
int32_t max_num_epochs |
Maximum number of iterations over the training set during wake-sleep training. Defualt value is 1
Definition at line 316 of file DeepBeliefNetwork.h.
int32_t monitoring_interval |
Number of weight updates between each evaluation of the reconstruction error during wake-sleep training. Default value is 10.
Definition at line 311 of file DeepBeliefNetwork.h.
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parallel
Definition at line 372 of file SGObject.h.
SGVector<int32_t> pt_cd_num_steps |
CRBM::cd_num_steps for pre-training each RBM. Default value is 1 for all RBMs
Definition at line 246 of file DeepBeliefNetwork.h.
SGVector<bool> pt_cd_persistent |
CRBM::cd_persistent for pre-training each RBM. Default value is true for all RBMs
Definition at line 251 of file DeepBeliefNetwork.h.
SGVector<bool> pt_cd_sample_visible |
CRBM::cd_sample_visible for pre-training each RBM. Default value is false for all RBMs
Definition at line 256 of file DeepBeliefNetwork.h.
CRBM::gd_learning_rate for pre-training each RBM. Default value is 0.1 for all RBMs
Definition at line 291 of file DeepBeliefNetwork.h.
CRBM::gd_learning_rate_decay for pre-training each RBM. Default value is 1.0 for all RBMs
Definition at line 296 of file DeepBeliefNetwork.h.
SGVector<int32_t> pt_gd_mini_batch_size |
CRBM::gd_mini_batch_size for pre-training each RBM. Default value is 0 for all RBMs
Definition at line 286 of file DeepBeliefNetwork.h.
CRBM::gd_momentum for pre-training each RBM. Default value is 0.9 for all RBMs
Definition at line 301 of file DeepBeliefNetwork.h.
CRBM::l1_coefficient for pre-training each RBM. Default value is 0.0 for all RBMs
Definition at line 266 of file DeepBeliefNetwork.h.
CRBM::l2_coefficient for pre-training each RBM. Default value is 0.0 for all RBMs
Definition at line 261 of file DeepBeliefNetwork.h.
SGVector<int32_t> pt_max_num_epochs |
CRBM::max_num_epochs for pre-training each RBM. Default value is 1 for all RBMs
Definition at line 281 of file DeepBeliefNetwork.h.
SGVector<int32_t> pt_monitoring_interval |
CRBM::monitoring_interval for pre-training each RBM. Default value is 10 for all RBMs
Definition at line 271 of file DeepBeliefNetwork.h.
SGVector<int32_t> pt_monitoring_method |
CRBM::monitoring_method for pre-training each RBM. Default value is RBMMM_RECONSTRUCTION_ERROR for all RBMs
Definition at line 276 of file DeepBeliefNetwork.h.
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version
Definition at line 375 of file SGObject.h.