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CRBM Class Reference

Detailed Description

A Restricted Boltzmann Machine.

An RBM is an energy based probabilistic model. It consists of two groups of variables: the visible variables \( v \) and the hidden variables \( h \). The key assumption that RBMs make is that the hidden units are conditionally independent given the visible units, and vice versa.

The energy function for RBMs with binary visible units is defined as:

\[ E(v,h) = - b^T v - c^T h - h^T Wv \]

and for RBMs with gaussian (linear) visible units:

\[ E(v,h) = v^T v - b^T v - c^T h - h^T Wv \]

where \( b \) is the bias vector for the visible units, \( c \) is the bias vector for the hidden units, and \( W \) is the weight matrix.

The probability distribution is defined through the energy fucntion as:

\[ P(v,h) = \frac{exp(-E(v,h))}{\sum_{v,h} exp(-E(v,h))} \]

The above definitions along with the independence assumptions result in the following conditionals:

\[ P(h=1|v) = \frac{1}{1+exp(-Wv-c)} \quad \text{for binary hidden units} \]

\[ P(v=1|h) = \frac{1}{1+exp(-W^T h-b)} \quad \text{for binary visible units} \]

\[ P(v|h) \sim \mathcal{N} (W^T h + b,1) \quad \text{for gaussian visible units} \]

Note that when using gaussian visible units, the inputs should be normalized to have zero mean and unity standard deviation.

This class supports having multiple types of visible units in the same RBM. The visible units are divided into groups where each group can have its own type. The hidden units however are just one group of binary units.

Samples can be drawn from the model using Gibbs sampling.

Training is done using contrastive divergence [Hinton, 2002] or persistent contrastive divergence [Tieleman, 2008] (default).

Training progress can be monitored using the reconstruction error (default), which is the average squared difference between a training batch and the RBM's reconstruction of it. The reconstruction is generated using one step of gibbs sampling. Progress can also be monitored using the pseudo-log-likelihood which is an approximation to the log-likelihood. However, this is currently only supported for binary visible units.

The rows of the visible_state matrix are divided into groups, one for each group of visible units. For example, if we have 3 groups of visible units: group 0 with 10 units, group 1 with 5 units, and group 2 with 6 units, the states of group 0 will be stored in visible_state[0:10,:], the states of group 1 will stored in visible_state[10:15,:], and the states of group 2 will be stored in visible_state[15:21,:]. Note that the groups are numbered by the order in which they where added to the RBM using add_visible_group()

Definition at line 123 of file RBM.h.

Inheritance diagram for CRBM:
Inheritance graph
[legend]

Public Member Functions

 CRBM ()
 CRBM (int32_t num_hidden)
 CRBM (int32_t num_hidden, int32_t num_visible, ERBMVisibleUnitType visible_unit_type=RBMVUT_BINARY)
virtual ~CRBM ()
virtual void add_visible_group (int32_t num_units, ERBMVisibleUnitType unit_type)
virtual void initialize (float64_t sigma=0.01)
virtual void set_batch_size (int32_t batch_size)
virtual void train (CDenseFeatures< float64_t > *features)
virtual void sample (int32_t num_gibbs_steps=1, int32_t batch_size=1)
virtual CDenseFeatures
< float64_t > * 
sample_group (int32_t V, int32_t num_gibbs_steps=1, int32_t batch_size=1)
virtual void sample_with_evidence (int32_t E, CDenseFeatures< float64_t > *evidence, int32_t num_gibbs_steps=1)
virtual CDenseFeatures
< float64_t > * 
sample_group_with_evidence (int32_t V, int32_t E, CDenseFeatures< float64_t > *evidence, int32_t num_gibbs_steps=1)
virtual void reset_chain ()
virtual float64_t free_energy (SGMatrix< float64_t > visible, SGMatrix< float64_t > buffer=SGMatrix< float64_t >())
virtual void free_energy_gradients (SGMatrix< float64_t > visible, SGVector< float64_t > gradients, bool positive_phase=true, SGMatrix< float64_t > hidden_mean_given_visible=SGMatrix< float64_t >())
virtual void contrastive_divergence (SGMatrix< float64_t > visible_batch, SGVector< float64_t > gradients)
virtual float64_t reconstruction_error (SGMatrix< float64_t > visible, SGMatrix< float64_t > buffer=SGMatrix< float64_t >())
virtual float64_t pseudo_likelihood (SGMatrix< float64_t > visible, SGMatrix< float64_t > buffer=SGMatrix< float64_t >())
virtual CDenseFeatures
< float64_t > * 
visible_state_features ()
virtual SGVector< float64_tget_parameters ()
virtual SGMatrix< float64_tget_weights (SGVector< float64_t > p=SGVector< float64_t >())
virtual SGVector< float64_tget_hidden_bias (SGVector< float64_t > p=SGVector< float64_t >())
virtual SGVector< float64_tget_visible_bias (SGVector< float64_t > p=SGVector< float64_t >())
virtual int32_t get_num_parameters ()
virtual const char * get_name () const
virtual CSGObjectshallow_copy () const
virtual CSGObjectdeep_copy () const
virtual bool is_generic (EPrimitiveType *generic) const
template<class T >
void set_generic ()
void unset_generic ()
virtual void print_serializable (const char *prefix="")
virtual bool save_serializable (CSerializableFile *file, const char *prefix="", int32_t param_version=Version::get_version_parameter())
virtual bool load_serializable (CSerializableFile *file, const char *prefix="", int32_t param_version=Version::get_version_parameter())
DynArray< TParameter * > * load_file_parameters (const SGParamInfo *param_info, int32_t file_version, CSerializableFile *file, const char *prefix="")
DynArray< TParameter * > * load_all_file_parameters (int32_t file_version, int32_t current_version, CSerializableFile *file, const char *prefix="")
void map_parameters (DynArray< TParameter * > *param_base, int32_t &base_version, DynArray< const SGParamInfo * > *target_param_infos)
void set_global_io (SGIO *io)
SGIOget_global_io ()
void set_global_parallel (Parallel *parallel)
Parallelget_global_parallel ()
void set_global_version (Version *version)
Versionget_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 CSGObjectclone ()

Public Attributes

int32_t cd_num_steps
bool cd_persistent
bool cd_sample_visible
float64_t l2_coefficient
float64_t l1_coefficient
int32_t monitoring_interval
ERBMMonitoringMethod monitoring_method
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
SGMatrix< float64_thidden_state
SGMatrix< float64_tvisible_state
SGIOio
Parallelparallel
Versionversion
Parameterm_parameters
Parameterm_model_selection_parameters
Parameterm_gradient_parameters
ParameterMapm_parameter_map
uint32_t m_hash

Protected Member Functions

virtual void mean_hidden (SGMatrix< float64_t > visible, SGMatrix< float64_t > result)
virtual void mean_visible (SGMatrix< float64_t > hidden, SGMatrix< float64_t > result)
virtual void sample_hidden (SGMatrix< float64_t > mean, SGMatrix< float64_t > result)
virtual void sample_visible (SGMatrix< float64_t > mean, SGMatrix< float64_t > result)
virtual void sample_visible (int32_t index, SGMatrix< float64_t > mean, SGMatrix< float64_t > result)
virtual TParametermigrate (DynArray< TParameter * > *param_base, const SGParamInfo *target)
virtual void one_to_one_migration_prepare (DynArray< TParameter * > *param_base, const SGParamInfo *target, TParameter *&replacement, TParameter *&to_migrate, char *old_name=NULL)
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

int32_t m_num_hidden
int32_t m_num_visible
int32_t m_batch_size
int32_t m_num_visible_groups
CDynamicArray< int32_t > * m_visible_group_types
CDynamicArray< int32_t > * m_visible_group_sizes
CDynamicArray< int32_t > * m_visible_state_offsets
int32_t m_num_params
SGVector< float64_tm_params

Friends

class CDeepBeliefNetwork

Constructor & Destructor Documentation

CRBM ( )

default constructor

Definition at line 44 of file RBM.cpp.

CRBM ( int32_t  num_hidden)

Constructs an RBM with no visible units. The visible units can be added later using add_visible_group()

Parameters
num_hiddenNumber of hidden units

Definition at line 49 of file RBM.cpp.

CRBM ( int32_t  num_hidden,
int32_t  num_visible,
ERBMVisibleUnitType  visible_unit_type = RBMVUT_BINARY 
)

Constructs an RBM with a single group of visible units

Parameters
num_hiddenNumber of hidden units
num_visibleNumber of visible units
visible_unit_typeType of the visible units

Definition at line 55 of file RBM.cpp.

~CRBM ( )
virtual

Definition at line 63 of file RBM.cpp.

Member Function Documentation

void add_visible_group ( int32_t  num_units,
ERBMVisibleUnitType  unit_type 
)
virtual

Adds a group of visible units to the RBM

Parameters
num_unitsNumber of visible units
visible_unit_typeType of the visible units

Definition at line 70 of file RBM.cpp.

void build_gradient_parameter_dictionary ( CMap< TParameter *, CSGObject * > *  dict)
inherited

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.

Parameters
dictdictionary of parameters to be built.

Definition at line 1189 of file SGObject.cpp.

CSGObject * clone ( )
virtualinherited

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.

Returns
an identical copy of the given object, which is disjoint in memory. NULL if the clone fails. Note that the returned object is SG_REF'ed

Definition at line 1306 of file SGObject.cpp.

void contrastive_divergence ( SGMatrix< float64_t visible_batch,
SGVector< float64_t gradients 
)
virtual

Computes the gradients using contrastive divergence

Parameters
visible_batchStates of the visible units
gradientsArray in which the results are stored. Length get_num_parameters()

Definition at line 356 of file RBM.cpp.

CSGObject * deep_copy ( ) const
virtualinherited

A deep copy. All the instance variables will also be copied.

Definition at line 146 of file SGObject.cpp.

bool equals ( CSGObject other,
float64_t  accuracy = 0.0,
bool  tolerant = false 
)
virtualinherited

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.

Parameters
otherobject to compare with
accuracyaccuracy to use for comparison (optional)
tolerantallows linient check on float equality (within accuracy)
Returns
true if all parameters were equal, false if not

Definition at line 1210 of file SGObject.cpp.

float64_t free_energy ( SGMatrix< float64_t visible,
SGMatrix< float64_t buffer = SGMatrix<float64_t>() 
)
virtual

Computes the average free energy on a given batch of visible unit states.

The free energy for a vector \( v \) is defined as:

\[ F(v) = - log(\sum_h exp(-E(v,h)) \]

which yields the following (in vectorized form):

\[ F(v) = -b^T v - \sum log(1+exp(Wv+c)) \quad \text{for binary visible units}\]

\[ F(v) = \frac{1}{2} v^T v - b^T v - \sum log(1+exp(Wv+c)) \quad \text{for gaussian visible units}\]

Parameters
visibleStates of the visible units
bufferA matrix of size num_hidden*batch_size. used as a buffer during computation. If not given, a new matrix is allocated and used as a buffer.
Returns
Average free energy over the given batch

Definition at line 273 of file RBM.cpp.

void free_energy_gradients ( SGMatrix< float64_t visible,
SGVector< float64_t gradients,
bool  positive_phase = true,
SGMatrix< float64_t hidden_mean_given_visible = SGMatrix<float64_t>() 
)
virtual

Computes the gradients of the free energy function with respect to the RBM's parameters

Parameters
visibleStates of the visible units
gradientsArray in which the results are stored. Length get_num_parameters()
positive_phaseIf true, the result vector is reset to zero and the gradients are added to it with a positive sign. If false, the result vector is not reset and the gradients are added to it with a negative sign. This is useful during contrastive divergence.
hidden_mean_given_visibleMeans of the hidden states given the visible states. If not given, means will be computed by calling mean_hidden()

Definition at line 319 of file RBM.cpp.

SGIO * get_global_io ( )
inherited

get the io object

Returns
io object

Definition at line 183 of file SGObject.cpp.

Parallel * get_global_parallel ( )
inherited

get the parallel object

Returns
parallel object

Definition at line 224 of file SGObject.cpp.

Version * get_global_version ( )
inherited

get the version object

Returns
version object

Definition at line 237 of file SGObject.cpp.

SGVector< float64_t > get_hidden_bias ( SGVector< float64_t p = SGVector<float64_t>())
virtual

Returns the bias vector of the hidden units

Parameters
pIf specified, the bias vector is extracted from it instead of m_params

Definition at line 581 of file RBM.cpp.

SGStringList< char > get_modelsel_names ( )
inherited
Returns
vector of names of all parameters which are registered for model selection

Definition at line 1081 of file SGObject.cpp.

char * get_modsel_param_descr ( const char *  param_name)
inherited

Returns description of a given parameter string, if it exists. SG_ERROR otherwise

Parameters
param_namename of the parameter
Returns
description of the parameter

Definition at line 1105 of file SGObject.cpp.

index_t get_modsel_param_index ( const char *  param_name)
inherited

Returns index of model selection parameter with provided index

Parameters
param_namename of model selection parameter
Returns
index of model selection parameter with provided name, -1 if there is no such

Definition at line 1118 of file SGObject.cpp.

virtual const char* get_name ( ) const
virtual

Returns the name of the SGSerializable instance. It MUST BE the CLASS NAME without the prefixed `C'.

Returns
name of the SGSerializable

Implements CSGObject.

Definition at line 347 of file RBM.h.

virtual int32_t get_num_parameters ( )
virtual

Returns the number of parameters

Definition at line 345 of file RBM.h.

virtual SGVector<float64_t> get_parameters ( )
virtual

Returns the parameter vector of the RBM

Definition at line 318 of file RBM.h.

SGVector< float64_t > get_visible_bias ( SGVector< float64_t p = SGVector<float64_t>())
virtual

Returns the bias vector of the visible units

Parameters
pIf specified, the bias vector is extracted from it instead of m_params

Definition at line 591 of file RBM.cpp.

SGMatrix< float64_t > get_weights ( SGVector< float64_t p = SGVector<float64_t>())
virtual

Returns the weights matrix

Parameters
pIf specified, the weight matrix is extracted from it instead of m_params

Definition at line 571 of file RBM.cpp.

void initialize ( float64_t  sigma = 0.01)
virtual

Initializes the weights of the RBM. Must be called after all the visible groups have been added, and before the RBM is used.

Parameters
sigmaStandard deviation of the gaussian used to initialize the weights

Definition at line 87 of file RBM.cpp.

bool is_generic ( EPrimitiveType *  generic) const
virtualinherited

If the SGSerializable is a class template then TRUE will be returned and GENERIC is set to the type of the generic.

Parameters
genericset to the type of the generic if returning TRUE
Returns
TRUE if a class template.

Definition at line 243 of file SGObject.cpp.

DynArray< TParameter * > * load_all_file_parameters ( int32_t  file_version,
int32_t  current_version,
CSerializableFile file,
const char *  prefix = "" 
)
inherited

maps all parameters of this instance to the provided file version and loads all parameter data from the file into an array, which is sorted (basically calls load_file_parameter(...) for all parameters and puts all results into a sorted array)

Parameters
file_versionparameter version of the file
current_versionversion from which mapping begins (you want to use Version::get_version_parameter() for this in most cases)
filefile to load from
prefixprefix for members
Returns
(sorted) array of created TParameter instances with file data

Definition at line 650 of file SGObject.cpp.

DynArray< TParameter * > * load_file_parameters ( const SGParamInfo param_info,
int32_t  file_version,
CSerializableFile file,
const char *  prefix = "" 
)
inherited

loads some specified parameters from a file with a specified version The provided parameter info has a version which is recursively mapped until the file parameter version is reached. Note that there may be possibly multiple parameters in the mapping, therefore, a set of TParameter instances is returned

Parameters
param_infoinformation of parameter
file_versionparameter version of the file, must be <= provided parameter version
filefile to load from
prefixprefix for members
Returns
new array with TParameter instances with the attached data

Definition at line 491 of file SGObject.cpp.

bool load_serializable ( CSerializableFile file,
const char *  prefix = "",
int32_t  param_version = Version::get_version_parameter() 
)
virtualinherited

Load this object from file. If it will fail (returning FALSE) then this object will contain inconsistent data and should not be used!

Parameters
filewhere to load from
prefixprefix for members
param_version(optional) a parameter version different to (this is mainly for testing, better do not use)
Returns
TRUE if done, otherwise FALSE

Definition at line 320 of file SGObject.cpp.

void load_serializable_post ( ) throw (ShogunException)
protectedvirtualinherited

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.

Exceptions
ShogunExceptionwill be thrown if an error occurs.

Reimplemented in CKernel, CWeightedDegreePositionStringKernel, CList, CAlphabet, CLinearHMM, CGaussianKernel, CInverseMultiQuadricKernel, CCircularKernel, and CExponentialKernel.

Definition at line 1008 of file SGObject.cpp.

void load_serializable_pre ( ) throw (ShogunException)
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.

Exceptions
ShogunExceptionwill 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 1003 of file SGObject.cpp.

void map_parameters ( DynArray< TParameter * > *  param_base,
int32_t &  base_version,
DynArray< const SGParamInfo * > *  target_param_infos 
)
inherited

Takes a set of TParameter instances (base) with a certain version and a set of target parameter infos and recursively maps the base level wise to the current version using CSGObject::migrate(...). The base is replaced. After this call, the base version containing parameters should be of same version/type as the initial target parameter infos. Note for this to work, the migrate methods and all the internal parameter mappings have to match

Parameters
param_baseset of TParameter instances that are mapped to the provided target parameter infos
base_versionversion of the parameter base
target_param_infosset of SGParamInfo instances that specify the target parameter base

Definition at line 688 of file SGObject.cpp.

void mean_hidden ( SGMatrix< float64_t visible,
SGMatrix< float64_t result 
)
protectedvirtual

Computes the mean of the hidden states given the visible states

Definition at line 451 of file RBM.cpp.

void mean_visible ( SGMatrix< float64_t hidden,
SGMatrix< float64_t result 
)
protectedvirtual

Computes the mean of the visible states given the hidden states

Definition at line 469 of file RBM.cpp.

TParameter * migrate ( DynArray< TParameter * > *  param_base,
const SGParamInfo target 
)
protectedvirtualinherited

creates a new TParameter instance, which contains migrated data from the version that is provided. The provided parameter data base is used for migration, this base is a collection of all parameter data of the previous version. Migration is done FROM the data in param_base TO the provided param info Migration is always one version step. Method has to be implemented in subclasses, if no match is found, base method has to be called.

If there is an element in the param_base which equals the target, a copy of the element is returned. This represents the case when nothing has changed and therefore, the migrate method is not overloaded in a subclass

Parameters
param_baseset of TParameter instances to use for migration
targetparameter info for the resulting TParameter
Returns
a new TParameter instance with migrated data from the base of the type which is specified by the target parameter

Definition at line 895 of file SGObject.cpp.

void one_to_one_migration_prepare ( DynArray< TParameter * > *  param_base,
const SGParamInfo target,
TParameter *&  replacement,
TParameter *&  to_migrate,
char *  old_name = NULL 
)
protectedvirtualinherited

This method prepares everything for a one-to-one parameter migration. One to one here means that only ONE element of the parameter base is needed for the migration (the one with the same name as the target). Data is allocated for the target (in the type as provided in the target SGParamInfo), and a corresponding new TParameter instance is written to replacement. The to_migrate pointer points to the single needed TParameter instance needed for migration. If a name change happened, the old name may be specified by old_name. In addition, the m_delete_data flag of to_migrate is set to true. So if you want to migrate data, the only thing to do after this call is converting the data in the m_parameter fields. If unsure how to use - have a look into an example for this. (base_migration_type_conversion.cpp for example)

Parameters
param_baseset of TParameter instances to use for migration
targetparameter info for the resulting TParameter
replacement(used as output) here the TParameter instance which is returned by migration is created into
to_migratethe only source that is used for migration
old_namewith this parameter, a name change may be specified

Definition at line 835 of file SGObject.cpp.

bool parameter_hash_changed ( )
virtualinherited
Returns
whether parameter combination has changed since last update

Definition at line 209 of file SGObject.cpp.

void print_modsel_params ( )
inherited

prints all parameter registered for model selection and their type

Definition at line 1057 of file SGObject.cpp.

void print_serializable ( const char *  prefix = "")
virtualinherited

prints registered parameters out

Parameters
prefixprefix for members

Definition at line 255 of file SGObject.cpp.

float64_t pseudo_likelihood ( SGMatrix< float64_t visible,
SGMatrix< float64_t buffer = SGMatrix<float64_t>() 
)
virtual

Computes an approximation to the pseudo-likelihood. See this tutorial for more details. Only works with binary visible units

Parameters
visibleStates of the visible units
bufferA matrix of size num_visible*batch_size. used as a buffer during computation. If not given, a new matrix is allocated and used as a buffer.
returnApproximation to the average pseudo-likelihood over the given batch

Definition at line 421 of file RBM.cpp.

float64_t reconstruction_error ( SGMatrix< float64_t visible,
SGMatrix< float64_t buffer = SGMatrix<float64_t>() 
)
virtual

Computes the average reconstruction error which is defined as:

\[ E = \frac{1}{N} \sum_i (v_i - \widetilde{v})^2 \]

where \( \widetilde{v} \) is computed using one step of gibbs sampling and \( N \) is the batch size

Returns
Average reconstruction error over the given batch

Definition at line 399 of file RBM.cpp.

void reset_chain ( )
virtual

Resets the state of the markov chain used for sampling, which is stored in the visible_state matrix, to random values

Definition at line 266 of file RBM.cpp.

void sample ( int32_t  num_gibbs_steps = 1,
int32_t  batch_size = 1 
)
virtual

Draws samples from the marginal distribution of the visible units using Gibbs sampling. The sampling starts from the values in the RBM's visible_state matrix and result of the sampling is stored there too.

Parameters
num_gibbs_stepsNumber of Gibbs sampling steps
batch_sizeNumber of samples to be drawn. A seperate chain is used for each sample

Definition at line 179 of file RBM.cpp.

CDenseFeatures< float64_t > * sample_group ( int32_t  V,
int32_t  num_gibbs_steps = 1,
int32_t  batch_size = 1 
)
virtual

Draws Samples from \( P(V) \) where \( V \) is one of the visible unit groups. The sampling starts from the values in the RBM's visible_state matrix and result of the sampling is stored there too.

Parameters
VIndex of the visible unit group to be sampled
num_gibbs_stepsNumber of Gibbs sampling steps
batch_sizeNumber of samples to be drawn. A seperate chain is used for each sample
Returns
Sampled states of group V

Definition at line 194 of file RBM.cpp.

CDenseFeatures< float64_t > * sample_group_with_evidence ( int32_t  V,
int32_t  E,
CDenseFeatures< float64_t > *  evidence,
int32_t  num_gibbs_steps = 1 
)
virtual

Draws Samples from \( P(V|E=evidence) \) where \( E \) is one of the visible unit groups and \( V \) is another visible unit group. The sampling starts from the values in the RBM's visible_state matrix and result of the sampling is stored there too.

Parameters
VIndex of the visible unit group to be sampled
EIndex of the evidence visible unit group
evidenceStates of the evidence visible unit group
num_gibbs_stepsNumber of Gibbs sampling steps
Returns
Sampled states of group V

Definition at line 246 of file RBM.cpp.

void sample_hidden ( SGMatrix< float64_t mean,
SGMatrix< float64_t result 
)
protectedvirtual

Samples the hidden states according to the provided means

Definition at line 520 of file RBM.cpp.

void sample_visible ( SGMatrix< float64_t mean,
SGMatrix< float64_t result 
)
protectedvirtual

Samples the visible states according to the provided means

Definition at line 527 of file RBM.cpp.

void sample_visible ( int32_t  index,
SGMatrix< float64_t mean,
SGMatrix< float64_t result 
)
protectedvirtual

Samples one group of visible states according to the provided means

Definition at line 535 of file RBM.cpp.

void sample_with_evidence ( int32_t  E,
CDenseFeatures< float64_t > *  evidence,
int32_t  num_gibbs_steps = 1 
)
virtual

Draws Samples from \( P(V|E=evidence) \) where \( E \) is one of the visible unit groups and \( V \) is all the visible unit excluding the ones in group \( E \). The sampling starts from the values in the RBM's visible_state matrix and result of the sampling is stored there too.

Parameters
EIndex of the evidence visible unit group
evidenceStates of the evidence visible unit group
num_gibbs_stepsNumber of Gibbs sampling steps

Definition at line 212 of file RBM.cpp.

bool save_serializable ( CSerializableFile file,
const char *  prefix = "",
int32_t  param_version = Version::get_version_parameter() 
)
virtualinherited

Save this object to file.

Parameters
filewhere to save the object; will be closed during returning if PREFIX is an empty string.
prefixprefix for members
param_version(optional) a parameter version different to (this is mainly for testing, better do not use)
Returns
TRUE if done, otherwise FALSE

Definition at line 261 of file SGObject.cpp.

void save_serializable_post ( ) throw (ShogunException)
protectedvirtualinherited

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.

Exceptions
ShogunExceptionwill be thrown if an error occurs.

Reimplemented in CKernel.

Definition at line 1018 of file SGObject.cpp.

void save_serializable_pre ( ) throw (ShogunException)
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.

Exceptions
ShogunExceptionwill 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 1013 of file SGObject.cpp.

void set_batch_size ( int32_t  batch_size)
virtual

Sets the number of train/test cases the RBM will deal with

Parameters
batch_sizeBatch size

Definition at line 96 of file RBM.cpp.

void set_generic< complex128_t > ( )
inherited

set generic type to T

Definition at line 38 of file SGObject.cpp.

void set_global_io ( SGIO io)
inherited

set the io object

Parameters
ioio object to use

Definition at line 176 of file SGObject.cpp.

void set_global_parallel ( Parallel parallel)
inherited

set the parallel object

Parameters
parallelparallel object to use

Definition at line 189 of file SGObject.cpp.

void set_global_version ( Version version)
inherited

set the version object

Parameters
versionversion object to use

Definition at line 230 of file SGObject.cpp.

CSGObject * shallow_copy ( ) const
virtualinherited

A shallow copy. All the SGObject instance variables will be simply assigned and SG_REF-ed.

Reimplemented in CGaussianKernel.

Definition at line 140 of file SGObject.cpp.

void train ( CDenseFeatures< float64_t > *  features)
virtual

Trains the RBM

Parameters
featuresInput features. Should have as many features as there are visible units in the RBM.

Definition at line 108 of file RBM.cpp.

void unset_generic ( )
inherited

unset generic type

this has to be called in classes specializing a template class

Definition at line 250 of file SGObject.cpp.

void update_parameter_hash ( )
virtualinherited

Updates the hash of current parameter combination

Definition at line 196 of file SGObject.cpp.

virtual CDenseFeatures<float64_t>* visible_state_features ( )
virtual

Returns the states of the visible unit as CDenseFeatures<float64_t>

Definition at line 312 of file RBM.h.

Friends And Related Function Documentation

friend class CDeepBeliefNetwork
friend

Definition at line 125 of file RBM.h.

Member Data Documentation

int32_t cd_num_steps

Number of Gibbs sampling steps performed before each weight update during training. Default value is 1.

Definition at line 373 of file RBM.h.

bool cd_persistent

If true, persistent contrastive divergence is used. Default value is true.

Definition at line 377 of file RBM.h.

bool cd_sample_visible

If true, the visible units are sampled during contrastive divergence. If false, the visible units are not sampled, and their mean values are used instead. Default value is false

Definition at line 383 of file RBM.h.

float64_t gd_learning_rate

gradient descent learning rate, defualt value 0.1

Definition at line 411 of file RBM.h.

float64_t gd_learning_rate_decay

gradient descent learning rate decay 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 418 of file RBM.h.

int32_t gd_mini_batch_size

size of the mini-batch used during gradient descent training, if 0 full-batch training is performed default value is 0

Definition at line 408 of file RBM.h.

float64_t gd_momentum

gradient descent momentum multiplier

default value is 0.9

For more details on momentum, see this paper [Sutskever, 2013]

Definition at line 428 of file RBM.h.

SGMatrix<float64_t> hidden_state

States of the hidden units

Definition at line 431 of file RBM.h.

SGIO* io
inherited

io

Definition at line 457 of file SGObject.h.

float64_t l1_coefficient

L1 Regularization coeff, default value is 0.0

Definition at line 389 of file RBM.h.

float64_t l2_coefficient

L2 Regularization coeff, default value is 0.0

Definition at line 386 of file RBM.h.

int32_t m_batch_size
protected

Batch size

Definition at line 444 of file RBM.h.

Parameter* m_gradient_parameters
inherited

parameters wrt which we can compute gradients

Definition at line 472 of file SGObject.h.

uint32_t m_hash
inherited

Hash of parameter values

Definition at line 478 of file SGObject.h.

Parameter* m_model_selection_parameters
inherited

model selection parameters

Definition at line 469 of file SGObject.h.

int32_t m_num_hidden
protected

Number of hidden units

Definition at line 438 of file RBM.h.

int32_t m_num_params
protected

Number of parameters

Definition at line 459 of file RBM.h.

int32_t m_num_visible
protected

Number of visible units

Definition at line 441 of file RBM.h.

int32_t m_num_visible_groups
protected

Number of visible unit groups

Definition at line 447 of file RBM.h.

ParameterMap* m_parameter_map
inherited

map for different parameter versions

Definition at line 475 of file SGObject.h.

Parameter* m_parameters
inherited

parameters

Definition at line 466 of file SGObject.h.

SGVector<float64_t> m_params
protected

Parameters

Definition at line 462 of file RBM.h.

CDynamicArray<int32_t>* m_visible_group_sizes
protected

Size of each visible unit group

Definition at line 453 of file RBM.h.

CDynamicArray<int32_t>* m_visible_group_types
protected

Type of each visible unit group

Definition at line 450 of file RBM.h.

CDynamicArray<int32_t>* m_visible_state_offsets
protected

Row offsets for accessing the states of each visible unit groups

Definition at line 456 of file RBM.h.

int32_t max_num_epochs

maximum number of iterations over the training set. defualt value is 1

Definition at line 402 of file RBM.h.

int32_t monitoring_interval

Number of weight updates between each evaluation of the monitoring method. Default value is 10.

Definition at line 394 of file RBM.h.

ERBMMonitoringMethod monitoring_method

Monitoring method

Definition at line 397 of file RBM.h.

Parallel* parallel
inherited

parallel

Definition at line 460 of file SGObject.h.

Version* version
inherited

version

Definition at line 463 of file SGObject.h.

SGMatrix<float64_t> visible_state

States of the visible units

Definition at line 434 of file RBM.h.


The documentation for this class was generated from the following files:

SHOGUN Machine Learning Toolbox - Documentation