sits_uncertainty {sits}

Estimate classification uncertainty based on probs cube

Description

Calculate the uncertainty cube based on the probabilities produced by the classifier. Takes a probability cube as input. The uncertainty measure is relevant in the context of active leaning, and helps to increase the quantity and quality of training samples by providing information about the confidence of the model. The supported types of uncertainty are 'entropy', 'least', and 'margin'. 'entropy' is the difference between all predictions expressed as entropy, 'least' is the difference between 100 prediction, and 'margin' is the difference between the two most confident predictions.

Usage

sits_uncertainty(
  cube,
  ...,
  type = "entropy",
  multicores = 2L,
  memsize = 4L,
  output_dir,
  version = "v1"
)

## S3 method for class 'probs_cube'
sits_uncertainty(
  cube,
  ...,
  type = "entropy",
  multicores = 2,
  memsize = 4,
  output_dir,
  version = "v1"
)

## S3 method for class 'probs_vector_cube'
sits_uncertainty(
  cube,
  ...,
  type = "entropy",
  multicores = 2,
  memsize = 4,
  output_dir,
  version = "v1"
)

## Default S3 method:
sits_uncertainty(cube, ..., type, multicores, memsize, output_dir, version)

Arguments

cube

Probability data cube.

...

Other parameters for specific functions.

type

Method to measure uncertainty. See details.

multicores

Number of cores to run the function.

memsize

Maximum overall memory (in GB) to run the function.

output_dir

Output directory for image files.

version

Version of resulting image (in the case of multiple tests).

Value

An uncertainty data cube

Author(s)

Gilberto Camara, [e-mail]

Rolf Simoes, [e-mail]

Alber Sanchez, [e-mail]

References

Monarch, Robert Munro. Human-in-the-Loop Machine Learning: Active learning and annotation for human-centered AI. Simon and Schuster, 2021.

Examples

if (sits_run_examples()) {
    # create a random forest model
    rfor_model <- sits_train(samples_modis_ndvi, sits_rfor())
    # create a data cube from local files
    data_dir <- system.file("extdata/raster/mod13q1", package = "sits")
    cube <- sits_cube(
        source = "BDC",
        collection = "MOD13Q1-6",
        data_dir = data_dir
    )
    # classify a data cube
    probs_cube <- sits_classify(
        data = cube, ml_model = rfor_model, output_dir = tempdir()
    )
    # calculate uncertainty
    uncert_cube <- sits_uncertainty(probs_cube, output_dir = tempdir())
    # plot the resulting uncertainty cube
    plot(uncert_cube)
}