Gini Index impurity criterion. More...
#include <decision_tree.h>
Public Member Functions | |
| GiniCriterion (OutputsIdx_t n_outputs, ClassesIdx_t *n_classes, ClassesIdx_t n_classes_max, SamplesIdx_t n_samples, ClassWeights_t *class_weight) | |
| Create and initialize a new gini criterion. More... | |
| void | calculate_node_histogram (Classes_t *y, std::vector< SamplesIdx_t > &samples, SamplesIdx_t start, SamplesIdx_t end) |
| Calculate weighted class histograms for all outputs for current node. More... | |
| double | calculate_impurity (std::vector< Histogram_t > &histogram) |
| Calculate impurity of weighted class histogram using the Gini criterion. More... | |
| void | calculate_node_impurity () |
| Calculate impurity for all outputs of the current node. More... | |
| void | calculate_NA_histogram (Classes_t *y, std::vector< SamplesIdx_t > &samples, SamplesIdx_t pos) |
| Calculate class histograms for all outputs for the samples with missing values and the samples with values. More... | |
| void | calculate_NA_impurity () |
| Calculate impurity for all outputs of samples with missing values and samples with values. More... | |
| double | calculate_NA_impurity_improvement () |
| void | init_threshold_histograms () |
| void | init_threshold_values_histograms () |
| void | update_threshold_histograms (Classes_t *y, std::vector< SamplesIdx_t > &samples, SamplesIdx_t new_pos) |
| void | calculate_threshold_impurity () |
| Calculate impurity for all outputs of samples with values that are smaller and greater than a threshold. More... | |
| void | calculate_threshold_NA_impurity () |
| double | calculate_threshold_impurity_improvement () |
| double | calculate_threshold_values_impurity_improvement () |
| double | calculate_threshold_NA_left_impurity_improvement () |
| double | calculate_threshold_NA_right_impurity_improvement () |
| std::vector< std::vector< Histogram_t > > | get_node_weighted_histogram () |
| double | get_node_impurity () |
| double | get_node_impurity_NA () |
| double | get_node_impurity_values () |
| double | get_node_impurity_threshold_left () |
| double | get_node_impurity_threshold_right () |
Detailed Description
Gini Index impurity criterion.
Constructor & Destructor Documentation
◆ GiniCriterion()
| koho::GiniCriterion::GiniCriterion | ( | OutputsIdx_t | n_outputs, |
| ClassesIdx_t * | n_classes, | ||
| ClassesIdx_t | n_classes_max, | ||
| SamplesIdx_t | n_samples, | ||
| ClassWeights_t * | class_weight | ||
| ) |
Create and initialize a new gini criterion.
Assuming: y[o] is 0, 1, 2, ... (n_classes[o] - 1) for all outputs o.
Member Function Documentation
◆ calculate_impurity()
| double koho::GiniCriterion::calculate_impurity | ( | std::vector< Histogram_t > & | histogram | ) |
Calculate impurity of weighted class histogram using the Gini criterion.
◆ calculate_NA_histogram()
| void koho::GiniCriterion::calculate_NA_histogram | ( | Classes_t * | y, |
| std::vector< SamplesIdx_t > & | samples, | ||
| SamplesIdx_t | pos | ||
| ) |
Calculate class histograms for all outputs for the samples with missing values and the samples with values.
Assuming: number of missing values > 0
◆ calculate_NA_impurity()
| void koho::GiniCriterion::calculate_NA_impurity | ( | ) |
Calculate impurity for all outputs of samples with missing values and samples with values.
Assuming: number of missing values > 0
Assuming: calculate_NA_histogram()
◆ calculate_NA_impurity_improvement()
| double koho::GiniCriterion::calculate_NA_impurity_improvement | ( | ) |
Calculate impurity improvement over all outputs from the current node to its children assuming a split between missing values and values. Assuming: number of missing values > 0
Assuming: calculate_node_impurity(), calculate_NA_impurity()
◆ calculate_node_histogram()
| void koho::GiniCriterion::calculate_node_histogram | ( | Classes_t * | y, |
| std::vector< SamplesIdx_t > & | samples, | ||
| SamplesIdx_t | start, | ||
| SamplesIdx_t | end | ||
| ) |
Calculate weighted class histograms for all outputs for current node.
◆ calculate_node_impurity()
| void koho::GiniCriterion::calculate_node_impurity | ( | ) |
Calculate impurity for all outputs of the current node.
Assuming: calculate_node_histogram()
◆ calculate_threshold_impurity()
| void koho::GiniCriterion::calculate_threshold_impurity | ( | ) |
Calculate impurity for all outputs of samples with values that are smaller and greater than a threshold.
Assuming: update_threshold_histograms()
◆ calculate_threshold_impurity_improvement()
| double koho::GiniCriterion::calculate_threshold_impurity_improvement | ( | ) |
Calculate the impurity improvement over all outputs from the current node to its children assuming a split of the samples with values smaller and greater than a threshold in the case that all samples have values. Assuming: calculate_node_impurity(), calculate_threshold_impurity()
◆ calculate_threshold_NA_impurity()
| void koho::GiniCriterion::calculate_threshold_NA_impurity | ( | ) |
Calculate the impurity for all outputs of samples with values that are smaller and greater than a threshold and passing on the samples with missing values. Assuming: number of missing values > 0
Assuming: update_threshold_histograms(), calculate_NA_histograms()
◆ calculate_threshold_NA_left_impurity_improvement()
| double koho::GiniCriterion::calculate_threshold_NA_left_impurity_improvement | ( | ) |
Calculate the impurity improvement over all outputs from the current node to its children assuming a split of the samples with values smaller and greater than a threshold and passing on the samples with missing values to the left child. Assuming: calculate_NA_impurity(), calculate_threshold_impurity(), calculate_threshold_NA_impurity()
◆ calculate_threshold_NA_right_impurity_improvement()
| double koho::GiniCriterion::calculate_threshold_NA_right_impurity_improvement | ( | ) |
Calculate the impurity improvement over all outputs from the current node to its children assuming a split of the samples with values smaller and greater than a threshold and passing on the samples with missing values to the right child. Assuming: calculate_NA_impurity(), calculate_threshold_impurity(), calculate_threshold_NA_impurity()
◆ calculate_threshold_values_impurity_improvement()
| double koho::GiniCriterion::calculate_threshold_values_impurity_improvement | ( | ) |
Calculate the impurity improvement over all outputs from the current node to its children assuming a split of the samples with values smaller and greater than a threshold in the case that there are also samples with missing values. Assuming: calculate_NA_impurity(), calculate_threshold_impurity()
◆ get_node_impurity()
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◆ get_node_impurity_NA()
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◆ get_node_impurity_threshold_left()
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◆ get_node_impurity_threshold_right()
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◆ get_node_impurity_values()
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◆ get_node_weighted_histogram()
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◆ init_threshold_histograms()
| void koho::GiniCriterion::init_threshold_histograms | ( | ) |
Initialize class histograms for all outputs for using a threshold on samples with values, in the case that all samples have values. Assuming: calculate_node_histogram()
◆ init_threshold_values_histograms()
| void koho::GiniCriterion::init_threshold_values_histograms | ( | ) |
Initialize class histograms for all outputs for using a threshold on samples with values, in the case that there are also samples with missing values. Assuming: number of missing values > 0
Assuming: calculate_NA_histogram()
◆ update_threshold_histograms()
| void koho::GiniCriterion::update_threshold_histograms | ( | Classes_t * | y, |
| std::vector< SamplesIdx_t > & | samples, | ||
| SamplesIdx_t | new_pos | ||
| ) |
Update class histograms for all outputs for using a threshold on values, from current position to the new position (correspond to thresholds). Assuming: new_pos > pos
Assuming: init_threshold_histograms() or init_threshold_values_histograms()
Member Data Documentation
◆ class_weight
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◆ n_classes
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◆ n_classes_max
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◆ n_outputs
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◆ n_samples
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◆ node_impurity
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◆ node_impurity_NA
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◆ node_impurity_threshold_left
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◆ node_impurity_threshold_left_NA
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◆ node_impurity_threshold_right
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◆ node_impurity_threshold_right_NA
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◆ node_impurity_values
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◆ node_pos_NA
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◆ node_pos_threshold
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◆ node_weighted_histogram
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◆ node_weighted_histogram_NA
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◆ node_weighted_histogram_threshold_left
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◆ node_weighted_histogram_threshold_right
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◆ node_weighted_histogram_values
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◆ node_weighted_n_samples
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◆ node_weighted_n_samples_NA
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◆ node_weighted_n_samples_threshold_left
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◆ node_weighted_n_samples_threshold_left_NA
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◆ node_weighted_n_samples_threshold_right
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◆ node_weighted_n_samples_threshold_right_NA
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◆ node_weighted_n_samples_values
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The documentation for this class was generated from the following files:
