sits_sample

Takes a sits tibble with different labels and
 returns a new tibble. For a given field as a group criterion,
 this new tibble contains a given number or percentage
 of the total number of samples per group.
 Parameter n: number of random samples.
 Parameter frac: a fraction of random samples.
 If n is greater than the number of samples for a given label,
 that label will be sampled with replacement. Also,
 if frac &gt; 1 , all sampling will be done with replacement.

An end-to-end toolkit for land use and land cover classification
using big Earth observation data, based on machine learning methods
applied to satellite image data cubes, as described in Simoes et al (2021) <doi:10.3390/rs13132428>.
Builds regular data cubes from collections in AWS, Microsoft Planetary Computer,
Brazil Data Cube, and Digital Earth Africa using the STAC protocol <https://stacspec.org/>
and the 'gdalcubes' R package <doi:10.3390/data4030092>.
Supports visualization methods for images and time series and
smoothing filters for dealing with noisy time series.
Includes functions for quality assessment of training samples using self-organized maps
as presented by Santos et al (2021) <doi:10.1016/j.isprsjprs.2021.04.014>.
Provides machine learning methods including support vector machines,
random forests, extreme gradient boosting, multi-layer perceptrons,
temporal convolutional neural networks <doi:10.3390/rs11050523>,
residual networks <arxiv:1809.04356>, and temporal attention encoders
<arXiv:2007.00586>.
Performs efficient classification of big Earth observation data cubes and includes
functions for post-classification smoothing based on Bayesian inference, and
methods for uncertainty assessment. Enables best
practices for estimating area and assessing accuracy of land change as
recommended by Olofsson et al(2014) <doi:10.1016/j.rse.2014.02.015>.
Minimum recommended requirements: 16 GB RAM and 4 CPU dual-core.

Gilberto Camara

sits

Satellite Image Time Series Analysis for Earth Observation Data
Cubes

Rolf Simoes

Felipe Souza

Lorena Santos

Pedro Andrade

Karine Ferreira

Alber Sanchez

Gilberto Queiroz

sits_sample function

<dl><dt>data</dt>
<dd>Input sits tibble.</dd>
<dt>n</dt>
<dd>Number of samples to pick from each group of data.</dd>
<dt>frac</dt>
<dd>Percentage of samples to pick from each group of data.</dd>
<dt>oversample</dt>
<dd>Oversample classes with small number of samples?</dd></dl>

Arguments

Rolf Simoes, <a href="/link/rolf.simoes%40inpe.br?package=sits&version=1.1.0" data-mini-rdoc="sits::rolf.simoes@inpe.br">rolf.simoes@inpe.br</a>

Author

Sample a percentage of a time series — sits_sample

<dl>

<dt>data</dt>
<dd>Input sits tibble.</dd>


<dt>n</dt>
<dd>Number of samples to pick from each group of data.</dd>


<dt>frac</dt>
<dd>Percentage of samples to pick from each group of data.</dd>


<dt>oversample</dt>
<dd>Oversample classes with small number of samples?</dd>

</dl>

Rolf Simoes, <a href='mailto:rolf.simoes@inpe.br'>rolf.simoes@inpe.br</a>

sits_sample: Sample a percentage of a time series

Description

Usage

Value

Arguments

Author

Examples