SHOGUN
3.2.1
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This class implements the CHAID algorithm proposed by Kass (1980) for decision tree learning. CHAID consists of three steps: merging, splitting and stopping. A tree is grown by repeatedly using these three steps on each node starting from the root node. CHAID accepts nominal or ordinal categorical predictors only. If predictors are continuous, they have to be transformed into ordinal predictors before tree growing.
CONVERTING CONTINUOUS PREDICTORS TO ORDINAL :
Continuous predictors are converted to ordinal by binning. The number of bins (K) has to be supplied by the user. Given K, a predictor is split in such a way that all the bins get the same number (more or less) of distinct predictor values. The maximum feature value in each bin is used as a breakpoint.
MERGING :
During the merging step, allowable pairs of categories of a predictor are evaluated for similarity. If the similarity of a pair is above a threshold, the categories constituting the pair are merged into a single category. The process is repeated until there is no pair left having high similarity between its categories. Similarity between categories is evaluated using the p_value
SPLITTING :
The splitting step selects which predictor to be used to best split the node. Selection is accomplished by comparing the adjusted p_value associated with each predictor. The predictor that has the smallest adjusted p_value is chosen for splitting the node.
STOPPING :
The tree growing process stops if any of the following conditions is satisfied :
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Definition at line 90 of file CHAIDTree.h.
Public Types | |
typedef CTreeMachineNode < CHAIDTreeNodeData > | node_t |
typedef CBinaryTreeMachineNode < CHAIDTreeNodeData > | bnode_t |
Public Attributes | |
SGIO * | io |
Parallel * | parallel |
Version * | version |
Parameter * | m_parameters |
Parameter * | m_model_selection_parameters |
Parameter * | m_gradient_parameters |
ParameterMap * | m_parameter_map |
uint32_t | m_hash |
Static Public Attributes | |
static const float64_t | MISSING =CMath::MAX_REAL_NUMBER |
Protected Member Functions | |
virtual bool | train_machine (CFeatures *data=NULL) |
virtual void | store_model_features () |
virtual bool | train_require_labels () const |
virtual TParameter * | migrate (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 | |
CTreeMachineNode < CHAIDTreeNodeData > * | m_root |
CDynamicObjectArray * | m_machines |
float64_t | m_max_train_time |
CLabels * | m_labels |
ESolverType | m_solver_type |
bool | m_store_model_features |
bool | m_data_locked |
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bnode_t type- Tree node with max 2 possible children
Definition at line 55 of file TreeMachine.h.
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node_t type- Tree node with many possible children
Definition at line 52 of file TreeMachine.h.
CCHAIDTree | ( | ) |
default constructor
Definition at line 39 of file CHAIDTree.cpp.
CCHAIDTree | ( | int32_t | dependent_vartype | ) |
constructor
dependent_vartype | feature type for dependent variable (0-nominal, 1-ordinal or 2-continuous) |
Definition at line 45 of file CHAIDTree.cpp.
CCHAIDTree | ( | int32_t | dependent_vartype, |
SGVector< int32_t > | feature_types, | ||
int32_t | num_breakpoints = 0 |
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constructor
dependent_vartype | feature type for dependent variable (0-nominal, 1-ordinal or 2-continuous) |
feature_types | type of various attributes (0-nominal, 1-ordinal or 2-continuous) |
num_breakpoints | number of breakpoints for continuous to ordinal conversion of attributes |
Definition at line 52 of file CHAIDTree.cpp.
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destructor
Definition at line 61 of file CHAIDTree.cpp.
apply machine to data if data is not specified apply to the current features
data | (test)data to be classified |
Definition at line 160 of file Machine.cpp.
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apply machine to data in means of binary classification problem
Reimplemented in CKernelMachine, COnlineLinearMachine, CWDSVMOcas, CNeuralNetwork, CLinearMachine, CDomainAdaptationSVMLinear, CPluginEstimate, CGaussianProcessBinaryClassification, and CBaggingMachine.
Definition at line 216 of file Machine.cpp.
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apply machine to data in means of latent problem
Reimplemented in CLinearLatentMachine.
Definition at line 240 of file Machine.cpp.
Applies a locked machine on a set of indices. Error if machine is not locked
indices | index vector (of locked features) that is predicted |
Definition at line 195 of file Machine.cpp.
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applies a locked machine on a set of indices for binary problems
Reimplemented in CKernelMachine, and CMultitaskLinearMachine.
Definition at line 246 of file Machine.cpp.
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applies a locked machine on a set of indices for latent problems
Definition at line 274 of file Machine.cpp.
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applies a locked machine on a set of indices for multiclass problems
Definition at line 260 of file Machine.cpp.
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applies a locked machine on a set of indices for regression problems
Reimplemented in CKernelMachine.
Definition at line 253 of file Machine.cpp.
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applies a locked machine on a set of indices for structured problems
Definition at line 267 of file Machine.cpp.
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classify data using Classification Tree NOTE : This method replaces all values of continuous attributes in supplied data with the actual breakpoint values used for classification
data | data to be classified |
Reimplemented from CMachine.
Definition at line 99 of file CHAIDTree.cpp.
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applies to one vector
Reimplemented in CKernelMachine, CRelaxedTree, CWDSVMOcas, COnlineLinearMachine, CLinearMachine, CMultitaskLinearMachine, CMulticlassMachine, CKNN, CDistanceMachine, CMultitaskLogisticRegression, CMultitaskLeastSquaresRegression, CScatterSVM, CGaussianNaiveBayes, CPluginEstimate, and CFeatureBlockLogisticRegression.
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Get regression labels using Regression Tree NOTE : This method replaces all values of continuous attributes in supplied data with the actual breakpoint values used for classification
data | data whose regression output is needed |
Reimplemented from CMachine.
Definition at line 106 of file CHAIDTree.cpp.
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apply machine to data in means of SO classification problem
Reimplemented in CLinearStructuredOutputMachine.
Definition at line 234 of file Machine.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 1185 of file SGObject.cpp.
void clear_feature_types | ( | ) |
clear feature types of various features
Definition at line 143 of file CHAIDTree.cpp.
void clear_weights | ( | ) |
clear weights of data points
Definition at line 127 of file CHAIDTree.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 1302 of file SGObject.cpp.
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Locks the machine on given labels and data. After this call, only train_locked and apply_locked may be called
Only possible if supports_locking() returns true
labs | labels used for locking |
features | features used for locking |
Reimplemented in CKernelMachine.
Definition at line 120 of file Machine.cpp.
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Unlocks a locked machine and restores previous state
Reimplemented in CKernelMachine.
Definition at line 151 of file Machine.cpp.
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A deep copy. All the instance variables will also be copied.
Definition at line 146 of file SGObject.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 1206 of file SGObject.cpp.
float64_t get_alpha_merge | ( | ) | const |
float64_t get_alpha_split | ( | ) | const |
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get classifier type
Reimplemented in CLaRank, CDualLibQPBMSOSVM, CNeuralNetwork, CCCSOSVM, CLeastAngleRegression, CLDA, CKernelRidgeRegression, CLibLinearMTL, CBaggingMachine, CLibLinear, CLibSVR, CQDA, CKMeans, CGaussianNaiveBayes, CMCLDA, CLinearRidgeRegression, CGaussianProcessBinaryClassification, CKNN, CScatterSVM, CGaussianProcessRegression, CSGDQN, CSVMSGD, CSVMOcas, COnlineSVMSGD, CMKLMulticlass, CDomainAdaptationSVMLinear, CLeastSquaresRegression, CMKLRegression, CWDSVMOcas, CHierarchical, CMKLOneClass, CLibSVM, CStochasticSOSVM, CMKLClassification, CLPBoost, CPerceptron, CAveragedPerceptron, CLPM, CNewtonSVM, CGMNPSVM, CSVMLin, CMulticlassLibSVM, CLibSVMOneClass, CGPBTSVM, CMPDSVM, CGNPPSVM, and CCPLEXSVM.
Definition at line 100 of file Machine.cpp.
int32_t get_dependent_vartype | ( | ) | const |
get dependent variable type : 0 for nominal, 1 for ordinal and 2 for continuous
Definition at line 177 of file CHAIDTree.h.
SGVector< int32_t > get_feature_types | ( | ) | const |
get feature types of various features
Definition at line 138 of file CHAIDTree.cpp.
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get problem type - multiclass classification or regression
Reimplemented from CBaseMulticlassMachine.
Definition at line 65 of file CHAIDTree.cpp.
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int32_t get_min_node_size | ( | ) | const |
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Definition at line 1077 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 1101 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 1114 of file SGObject.cpp.
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get name
Reimplemented from CTreeMachine< CHAIDTreeNodeData >.
Definition at line 114 of file CHAIDTree.h.
float64_t get_num_breakpoints | ( | ) | const |
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get number of machines
Definition at line 27 of file BaseMulticlassMachine.cpp.
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int32_t get_specified_max_tree_depth | ( | ) | const |
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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 243 of file SGObject.cpp.
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whether labels supplied are valid for current problem type
lab | labels supplied |
Reimplemented from CBaseMulticlassMachine.
Definition at line 82 of file CHAIDTree.cpp.
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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)
file_version | parameter version of the file |
current_version | version from which mapping begins (you want to use Version::get_version_parameter() for this in most cases) |
file | file to load from |
prefix | prefix for members |
Definition at line 648 of file SGObject.cpp.
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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
param_info | information of parameter |
file_version | parameter version of the file, must be <= provided parameter version |
file | file to load from |
prefix | prefix for members |
Definition at line 489 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 |
param_version | (optional) a parameter version different to (this is mainly for testing, better do not use) |
Definition at line 320 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 occurres. |
Reimplemented in CKernel, CWeightedDegreePositionStringKernel, CList, CAlphabet, CLinearHMM, CGaussianKernel, CInverseMultiQuadricKernel, CCircularKernel, and CExponentialKernel.
Definition at line 1004 of file SGObject.cpp.
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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 occurres. |
Reimplemented in CDynamicArray< T >, CDynamicArray< float64_t >, CDynamicArray< float32_t >, CDynamicArray< int32_t >, CDynamicArray< char >, CDynamicArray< bool >, and CDynamicObjectArray.
Definition at line 999 of file SGObject.cpp.
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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
param_base | set of TParameter instances that are mapped to the provided target parameter infos |
base_version | version of the parameter base |
target_param_infos | set of SGParamInfo instances that specify the target parameter base |
Definition at line 686 of file SGObject.cpp.
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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
param_base | set of TParameter instances to use for migration |
target | parameter info for the resulting TParameter |
Definition at line 893 of file SGObject.cpp.
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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)
param_base | set of TParameter instances to use for migration |
target | parameter info for the resulting TParameter |
replacement | (used as output) here the TParameter instance which is returned by migration is created into |
to_migrate | the only source that is used for migration |
old_name | with this parameter, a name change may be specified |
Definition at line 833 of file SGObject.cpp.
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Definition at line 209 of file SGObject.cpp.
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prints all parameter registered for model selection and their type
Definition at line 1053 of file SGObject.cpp.
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prints registered parameters out
prefix | prefix for members |
Definition at line 255 of file SGObject.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 |
param_version | (optional) a parameter version different to (this is mainly for testing, better do not use) |
Definition at line 261 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 occurres. |
Reimplemented in CKernel.
Definition at line 1014 of file SGObject.cpp.
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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 occurres. |
Reimplemented in CKernel, CDynamicArray< T >, CDynamicArray< float64_t >, CDynamicArray< float32_t >, CDynamicArray< int32_t >, CDynamicArray< char >, CDynamicArray< bool >, and CDynamicObjectArray.
Definition at line 1009 of file SGObject.cpp.
void set_alpha_merge | ( | float64_t | a | ) |
void set_alpha_split | ( | float64_t | a | ) |
void set_dependent_vartype | ( | int32_t | var | ) |
set dependent variable type : 0 for nominal, 1 for ordinal and 2 for continuous
var | integer corresponding to the dependent variable type |
Definition at line 148 of file CHAIDTree.cpp.
void set_feature_types | ( | SGVector< int32_t > | ft | ) |
set feature types of various features
ft | vector with feature types : 0-nominal, 1-ordinal or 2-continuous |
Definition at line 133 of file CHAIDTree.cpp.
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Definition at line 38 of file SGObject.cpp.
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Definition at line 43 of file SGObject.cpp.
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Definition at line 48 of file SGObject.cpp.
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Definition at line 53 of file SGObject.cpp.
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Definition at line 58 of file SGObject.cpp.
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Definition at line 63 of file SGObject.cpp.
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Definition at line 68 of file SGObject.cpp.
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Definition at line 73 of file SGObject.cpp.
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Definition at line 78 of file SGObject.cpp.
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Definition at line 83 of file SGObject.cpp.
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Definition at line 88 of file SGObject.cpp.
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Definition at line 93 of file SGObject.cpp.
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Definition at line 98 of file SGObject.cpp.
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Definition at line 103 of file SGObject.cpp.
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Definition at line 108 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 189 of file SGObject.cpp.
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set the version object
version | version object to use |
Definition at line 230 of file SGObject.cpp.
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set labels
lab | labels |
Reimplemented in CNeuralNetwork, CCARTree, CGaussianProcessMachine, CStructuredOutputMachine, CRelaxedTree, and CMulticlassMachine.
Definition at line 73 of file Machine.cpp.
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set maximum training time
t | maximimum training time |
Definition at line 90 of file Machine.cpp.
void set_max_tree_depth | ( | int32_t | d | ) |
void set_min_node_size | ( | int32_t | size | ) |
void set_num_breakpoints | ( | int32_t | b | ) |
set number of breakpoints
b | number of breakpoints |
Definition at line 222 of file CHAIDTree.h.
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Setter for store-model-features-after-training flag
store_model | whether model should be stored after training |
Definition at line 115 of file Machine.cpp.
set weights of data points
w | vector of weights |
Definition at line 113 of file CHAIDTree.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 140 of file SGObject.cpp.
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enable unlocked cross-validation - no model features to store
Reimplemented from CMachine.
Definition at line 152 of file TreeMachine.h.
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Reimplemented in CKernelMachine, and CMultitaskLinearMachine.
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train machine
data | training data (parameter can be avoided if distance or kernel-based classifiers are used and distance/kernels are initialized with train data). If flag is set, model features will be stored after training. |
Reimplemented in CRelaxedTree, CAutoencoder, CSGDQN, and COnlineSVMSGD.
Definition at line 47 of file Machine.cpp.
Trains a locked machine on a set of indices. Error if machine is not locked
NOT IMPLEMENTED
indices | index vector (of locked features) that is used for training |
Reimplemented in CKernelMachine, and CMultitaskLinearMachine.
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train machine - build CHAID from training data
data | training data |
Reimplemented from CMachine.
Definition at line 154 of file CHAIDTree.cpp.
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returns whether machine require labels for training
Reimplemented in COnlineLinearMachine, CHierarchical, CLinearLatentMachine, CVwConditionalProbabilityTree, CConditionalProbabilityTree, and CLibSVMOneClass.
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unset generic type
this has to be called in classes specializing a template class
Definition at line 250 of file SGObject.cpp.
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Updates the hash of current parameter combination
Definition at line 196 of file SGObject.cpp.
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io
Definition at line 461 of file SGObject.h.
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parameters wrt which we can compute gradients
Definition at line 476 of file SGObject.h.
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Hash of parameter values
Definition at line 482 of file SGObject.h.
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machines
Definition at line 56 of file BaseMulticlassMachine.h.
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model selection parameters
Definition at line 473 of file SGObject.h.
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map for different parameter versions
Definition at line 479 of file SGObject.h.
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parameters
Definition at line 470 of file SGObject.h.
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tree root
Definition at line 156 of file TreeMachine.h.
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denotes that a feature in a vector is missing MISSING = MAX_REAL_NUMBER
Definition at line 393 of file CHAIDTree.h.
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parallel
Definition at line 464 of file SGObject.h.
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version
Definition at line 467 of file SGObject.h.