gpmp::ml::Kfold Class Reference

Represents a k-fold cross-validation utility. More...

#include <kfold.hpp>

Public Member Functions
	Kfold (int k)
	Constructor for the Kfold class. More...
	~Kfold ()
	Destructor for the Kfold class. More...
void	split_indices (int num_instances)
	Splits the indices of instances into k folds for cross-validation. More...
void	perform_cross_validation (std::function< void(int, int)> train_and_test_func)
	Performs k-fold cross-validation using the provided training and testing function. More...

Private Attributes
int	k
std::vector< std::vector< int > >	fold_indices

Detailed Description

Represents a k-fold cross-validation utility.

Definition at line 48 of file kfold.hpp.

Constructor & Destructor Documentation

Kfold()

gpmp::ml::Kfold::Kfold

(

int

k

)

Constructor for the Kfold class.

Parameters

k	The number of folds for cross-validation

Definition at line 39 of file kfold.cpp.

                           : k(fold) {
}

~Kfold()

gpmp::ml::Kfold::~Kfold

(

)

Destructor for the Kfold class.

Definition at line 42 of file kfold.cpp.

                    {
}

Member Function Documentation

perform_cross_validation()

void gpmp::ml::Kfold::perform_cross_validation

(

std::function< void(int, int)>

train_and_test_func

)

Performs k-fold cross-validation using the provided training and testing function.

Parameters

train_and_test_func

The function that trains and tests the model on given folds The function should take two integers as parameters: the index of the training fold and the index of the testing instance

Exceptions

std::logic_error

if indices are not split before performing cross-validation

Definition at line 68 of file kfold.cpp.

                                                     {
    if (fold_indices.empty()) {
        throw std::logic_error("Indices not split. Call split_indices before "
                               "performing cross-validation.");
    }
 
    for (int i = 0; i < k; ++i) {
        // Use fold i as the validation set, train on all other folds
        std::vector<int> validation_indices = fold_indices[i];
        for (int j = 0; j < k; ++j) {
            if (j != i) {
                for (int index : fold_indices[j]) {
                    train_and_test_func(j, index);
                }
            }
        }
    }
}

split_indices()

void gpmp::ml::Kfold::split_indices

(

int

num_instances

)

Splits the indices of instances into k folds for cross-validation.

Parameters

num_instances

The total number of instances

Exceptions

std::invalid_argument

if k or num_instances is invalid

Definition at line 45 of file kfold.cpp.

                                                 {
    if (k <= 1 || num_instances <= 0) {
        throw std::invalid_argument(
            "Invalid value of k or number of instances.");
    }
 
    // Initialize fold_indices with k empty vectors
    fold_indices.clear();
    fold_indices.resize(k);
 
    // Assign indices to each fold
    int fold_size = num_instances / k;
    int remainder = num_instances % k;
    int start_index = 0;
    for (int i = 0; i < k; ++i) {
        int fold_length = fold_size + (i < remainder ? 1 : 0);
        std::vector<int> indices(fold_length);
        std::iota(indices.begin(), indices.end(), start_index);
        fold_indices[i] = indices;
        start_index += fold_length;
    }
}

Member Data Documentation

fold_indices

std::vector<std::vector<int> > gpmp::ml::Kfold::fold_indices

private

Definition at line 84 of file kfold.hpp.

k

int gpmp::ml::Kfold::k

private

< The number of folds for cross-validation The indices of instances grouped into k folds

Definition at line 82 of file kfold.hpp.

---

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

• include/openGPMP/ml/kfold.hpp
• modules/ml/kfold.cpp