sits_kfold_validate: Cross-validate temporal patterns

Description Usage Arguments Value Author(s)

Description

Splits the set of time series into training and validation and perform k-fold cross-validation. Cross-validation is a model validation technique for assessing how the results of a statistical analysis will generalize to an independent data set. It is mainly used in settings where the goal is prediction, and one wants to estimate how accurately a predictive model will perform in practice. One round of cross-validation involves partitioning a sample of data into complementary subsets, performing the analysis on one subset (called the training set), and validating the analysis on the other subset (called the validation set or testing set).

The k-fold cross validation method involves splitting the dataset into k-subsets. For each subset is held out while the model is trained on all other subsets. This process is completed until accuracy is determine for each instance in the dataset, and an overall accuracy estimate is provided.

This function returns the Overall Accuracy, User's Accuracy, Producer's Accuracy, error matrix (confusion matrix), and Kappa values.

Usage

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sits_kfold_validate(data.tb, bands = NULL, folds = 5,
  pt_method = sits_gam(bands = bands),
  dist_method = sits_TWDTW_distances(bands = bands), tr_method = sits_svm(),
  multicores = 1)

Arguments

data.tb

a SITS tibble

bands

the bands used for classification

folds

number of partitions to create.

pt_method

method to create patterns (sits_patterns_gam, sits_dendogram)

dist_method

method to compute distances (e.g., sits_TWDTW_distances)

tr_method

machine learning training method

multicores

number of threads to process the validation (Linux only). Each process will run a whole partition validation.

Value

conf.tb a tibble containing pairs of reference and predicted values

Author(s)

Rolf Simoes, rolf.simoes@inpe.br

Gilberto Camara, gilberto.camara@inpe.br


luizassis/sits documentation built on May 30, 2019, 7:15 p.m.