ClassesClassesClassesClasses | | | | Operators

set_params_class_knnT_set_params_class_knnSetParamsClassKnnset_params_class_knnSetParamsClassKnnSetParamsClassKnn (Operator)

Name

set_params_class_knnT_set_params_class_knnSetParamsClassKnnset_params_class_knnSetParamsClassKnnSetParamsClassKnn — Set parameters for k-NN classification.

Signature

set_params_class_knn( : : KNNHandle, GenParamNames, GenParamValues : )

Herror T_set_params_class_knn(const Htuple KNNHandle, const Htuple GenParamNames, const Htuple GenParamValues)

Herror set_params_class_knn(const HTuple& KNNHandle, const HTuple& GenParamNames, const HTuple& GenParamValues)

void HClassKnn::SetParamsClassKnn(const HTuple& GenParamNames, const HTuple& GenParamValues) const

void SetParamsClassKnn(const HTuple& KNNHandle, const HTuple& GenParamNames, const HTuple& GenParamValues)

void HClassKnn::SetParamsClassKnn(const HTuple& GenParamNames, const HTuple& GenParamValues) const

void HOperatorSetX.SetParamsClassKnn(
[in] VARIANT KNNHandle, [in] VARIANT GenParamNames, [in] VARIANT GenParamValues)

void HClassKnnX.SetParamsClassKnn(
[in] VARIANT GenParamNames, [in] VARIANT GenParamValues)

static void HOperatorSet.SetParamsClassKnn(HTuple KNNHandle, HTuple genParamNames, HTuple genParamValues)

void HClassKnn.SetParamsClassKnn(HTuple genParamNames, HTuple genParamValues)

Description

set_params_class_knnset_params_class_knnSetParamsClassKnnset_params_class_knnSetParamsClassKnnSetParamsClassKnn sets parameters for the classification of the k-nearest neighbors (k-NN) classifier KNNHandleKNNHandleKNNHandleKNNHandleKNNHandleKNNHandle. It controls the behavior of classify_class_knnclassify_class_knnClassifyClassKnnclassify_class_knnClassifyClassKnnClassifyClassKnn.

The value of 'k'"k""k""k""k""k" can be set via GenParamNamesGenParamNamesGenParamNamesGenParamNamesGenParamNamesgenParamNames and GenParamValuesGenParamValuesGenParamValuesGenParamValuesGenParamValuesgenParamValues. Increasing 'k'"k""k""k""k""k" also increases the accuracy of the resulting neighbors and increases the run time.

The results can either be the determined class of the feature vector or the indices of the nearest neighbors. The result behavior can be selected with set_params_class_knnset_params_class_knnSetParamsClassKnnset_params_class_knnSetParamsClassKnnSetParamsClassKnn via the generic parameters 'method'"method""method""method""method""method" and 'max_num_classes'"max_num_classes""max_num_classes""max_num_classes""max_num_classes""max_num_classes":

'classes_distance'"classes_distance""classes_distance""classes_distance""classes_distance""classes_distance":

returns the nearest samples for each of maximally 'max_num_classes'"max_num_classes""max_num_classes""max_num_classes""max_num_classes""max_num_classes" different classes, if they have a representative in the nearest 'k'"k""k""k""k""k" neighbors. The results are classes sorted by their minimal distance. There is no efficient way to determine in a k-NN-tree the nearest neighbor for exactly 'max_num_classes'"max_num_classes""max_num_classes""max_num_classes""max_num_classes""max_num_classes" classes.

'classes_frequency'"classes_frequency""classes_frequency""classes_frequency""classes_frequency""classes_frequency":

counts the occurrences of certain classes among the nearest 'k'"k""k""k""k""k" neighbors and returns the occurrent classes sorted by their relative frequency that is returned, too. Again, maximally 'max_num_classes'"max_num_classes""max_num_classes""max_num_classes""max_num_classes""max_num_classes" values are returned.

'classes_weighted_frequencies'"classes_weighted_frequencies""classes_weighted_frequencies""classes_weighted_frequencies""classes_weighted_frequencies""classes_weighted_frequencies":

counts the occurrences of certain classes among the nearest 'k'"k""k""k""k""k" neighbors and returns the occurrent classes sorted by their relative frequency weighted with the average distance that is returned, too. Again, maximally 'max_num_classes'"max_num_classes""max_num_classes""max_num_classes""max_num_classes""max_num_classes" values are returned.

'neighbors_distance'"neighbors_distance""neighbors_distance""neighbors_distance""neighbors_distance""neighbors_distance":

returns the indices of the nearest 'k'"k""k""k""k""k" neighbors and the distances.

The default behavior is 'classes_distance'"classes_distance""classes_distance""classes_distance""classes_distance""classes_distance".

The option 'num_checks'"num_checks""num_checks""num_checks""num_checks""num_checks" allows to set the number of maximal runs through the trees. The parameter has to be positive and the default value is 32. The higher this value is, the more accurate the results will be. As a tradeoff, the running time will also be higher. Setting this parameter to 0 triggers an exact search.

The option 'epsilon'"epsilon""epsilon""epsilon""epsilon""epsilon" allows to set a stop criteria if the value is increased from the default value 0.0. The higher the value is set, the less accurate results of the estimated neighbors can be expected, while it might speed up the search.

Parallelization

This operator modifies the state of the following input parameter:

The value of this parameter may not be shared across multiple threads without external synchronization.

Parameters

KNNHandleKNNHandleKNNHandleKNNHandleKNNHandleKNNHandle (input_control, state is modified)  class_knn HClassKnn, HTupleHTupleHClassKnn, HTupleHClassKnnX, VARIANTHtuple (integer) (IntPtr) (Hlong) (Hlong) (Hlong) (Hlong)

Handle of the k-NN classifier.

GenParamNamesGenParamNamesGenParamNamesGenParamNamesGenParamNamesgenParamNames (input_control)  string-array HTupleHTupleHTupleVARIANTHtuple (string) (string) (HString) (char*) (BSTR) (char*)

Names of the generic parameters that can be adjusted for the k-NN classifier.

Default value: ['method','k','max_num_classes'] ["method","k","max_num_classes"] ["method","k","max_num_classes"] ["method","k","max_num_classes"] ["method","k","max_num_classes"] ["method","k","max_num_classes"]

List of values: 'epsilon'"epsilon""epsilon""epsilon""epsilon""epsilon", 'k'"k""k""k""k""k", 'max_num_classes'"max_num_classes""max_num_classes""max_num_classes""max_num_classes""max_num_classes", 'method'"method""method""method""method""method", 'num_checks'"num_checks""num_checks""num_checks""num_checks""num_checks"

GenParamValuesGenParamValuesGenParamValuesGenParamValuesGenParamValuesgenParamValues (input_control)  number-array HTupleHTupleHTupleVARIANTHtuple (integer / real / string) (int / long / double / string) (Hlong / double / HString) (Hlong / double / char*) (Hlong / double / BSTR) (Hlong / double / char*)

Values of the generic parameters that can be adjusted for the k-NN classifier.

Default value: ['classes_distance',5,1] ["classes_distance",5,1] ["classes_distance",5,1] ["classes_distance",5,1] ["classes_distance",5,1] ["classes_distance",5,1]

List of values: 32, 0.0, 0.02, 0, 1, 2, 3, 4, 5, 6, 'classes_distance'"classes_distance""classes_distance""classes_distance""classes_distance""classes_distance", 'classes_frequency'"classes_frequency""classes_frequency""classes_frequency""classes_frequency""classes_frequency", 'classes_weighted_frequencies'"classes_weighted_frequencies""classes_weighted_frequencies""classes_weighted_frequencies""classes_weighted_frequencies""classes_weighted_frequencies", 'neighbors_distance'"neighbors_distance""neighbors_distance""neighbors_distance""neighbors_distance""neighbors_distance"

Result

If the parameters are valid, the operator set_params_class_knnset_params_class_knnSetParamsClassKnnset_params_class_knnSetParamsClassKnnSetParamsClassKnn returns the value 2 (H_MSG_TRUE). If necessary, an exception is raised.

Possible Predecessors

train_class_knntrain_class_knnTrainClassKnntrain_class_knnTrainClassKnnTrainClassKnn, read_class_knnread_class_knnReadClassKnnread_class_knnReadClassKnnReadClassKnn

Possible Successors

classify_class_knnclassify_class_knnClassifyClassKnnclassify_class_knnClassifyClassKnnClassifyClassKnn

See also

create_class_knncreate_class_knnCreateClassKnncreate_class_knnCreateClassKnnCreateClassKnn, read_class_knnread_class_knnReadClassKnnread_class_knnReadClassKnnReadClassKnn, get_params_class_knnget_params_class_knnGetParamsClassKnnget_params_class_knnGetParamsClassKnnGetParamsClassKnn

References

Marius Muja, David G. Lowe: “Fast Approximate Nearest Neighbors with Automatic Algorithm Configuration”; International Conference on Computer Vision Theory and Applications (VISAPP 09); 2009.

Module

Foundation


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