gdalcubes/man/predict.cube.Rd
2024-03-04 20:39:45 +01:00

72 lines
2.9 KiB
R

% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/predict.R
\name{predict.cube}
\alias{predict.cube}
\title{Model prediction}
\usage{
\method{predict}{cube}(object, model, ..., output_names = c("pred"), keep_bands = FALSE)
}
\arguments{
\item{object}{a data cube proxy object (class cube)}
\item{model}{model used for prediction (e.g. from \code{caret} or \code{tidymodels})}
\item{...}{further arguments passed to the model-specific predict method}
\item{output_names}{optional character vector for output variable(s)}
\item{keep_bands}{logical; keep bands of input data cube, defaults to FALSE, i.e. original bands will be dropped}
}
\description{
Apply a trained model on all pixels of a data cube.
}
\details{
The model-specific predict method will be automatically chosen based on the class of the provided model. It aims at supporting
models from the packages \code{tidymodels}, \code{caret}, and simple models as from \code{lm} or \code{glm}.
For multiple output variables or output in form of lists or data.frames, \code{output_names} must be provided and match
names of the columns / items of the result object returned from the underlying predict method. For example,
predictions using \code{tidymodels} return a tibble (data.frame) with columns like \code{.pred_class} (classification case).
This must be explicitly provided as \code{output_names}. Similarly, \code{predict.lm} and the like return lists
if the standard error is requested by the user and \code{output_names} hence should be set to \code{c("fit","se.fit")}.
For more complex cases or when predict expects something else than a \code{data.frame}, this function may not work at all.
}
\note{
This function returns a proxy object, i.e., it will not immediately start any computations.
}
\examples{
\donttest{
# create image collection from example Landsat data only
# if not already done in other examples
if (!file.exists(file.path(tempdir(), "L8.db"))) {
L8_files <- list.files(system.file("L8NY18", package = "gdalcubes"),
".TIF", recursive = TRUE, full.names = TRUE)
create_image_collection(L8_files, "L8_L1TP", file.path(tempdir(), "L8.db"), quiet = TRUE)
}
v = cube_view(extent=list(left=388941.2, right=766552.4,
bottom=4345299, top=4744931, t0="2018-04", t1="2018-06"),
srs="EPSG:32618", nx = 497, ny=526, dt="P3M")
L8.col = image_collection(file.path(tempdir(), "L8.db"))
x = sf::st_read(system.file("ny_samples.gpkg", package = "gdalcubes"))
raster_cube(L8.col, v) |>
select_bands(c("B02","B03","B04","B05")) |>
extract_geom(x) -> train
x$FID = rownames(x)
train = merge(train, x, by = "FID")
train$iswater = as.factor(train$class == "water")
log_model <- glm(iswater ~ B02 + B03 + B04 + B05, data = train, family = "binomial")
raster_cube(L8.col, v) |>
select_bands(c("B02","B03","B04","B05")) |>
predict(model=log_model, type="response") |>
plot(key.pos=1)
}
}