stars (version 0.4-3)

st_apply: st_apply apply a function to one or more array dimensions

Description

st_apply apply a function to array dimensions: aggregate over space, time, or something else

Usage

# S3 method for stars
st_apply(
  X,
  MARGIN,
  FUN,
  ...,
  CLUSTER = NULL,
  PROGRESS = FALSE,
  FUTURE = FALSE,
  rename = TRUE
)

Arguments

X

object of class stars

MARGIN

see apply; index number(s) or name(s) of the dimensions over which FUN will be applied

FUN

see apply

...

arguments passed on to FUN

CLUSTER

cluster to use for parallel apply; see makeCluster

PROGRESS

logical; if TRUE, use pbapply::pbapply to show progress bar

FUTURE

logical;if TRUE, use future.apply::future_apply

rename

logical; if TRUE and X has only one attribute and FUN is a simple function name, rename the attribute of the returned object to the function name

Value

object of class stars with accordingly reduced number of dimensions; in case FUN returns more than one value, a new dimension is created carrying the name of the function used; see the examples.

Examples

# NOT RUN {
tif = system.file("tif/L7_ETMs.tif", package = "stars")
x = read_stars(tif)
st_apply(x, 1:2, mean) # mean band value for each pixel
st_apply(x, c("x", "y"), mean) # equivalent to the above
st_apply(x, 3, mean)   # mean of all pixels for each band
st_apply(x, "band", mean) # equivalent to the above
st_apply(x, 1:2, range) # min and max band value for each pixel
# to get a progress bar also in non-interactive mode, specify:
if (require(pbapply)) { # install it, if FALSE
  pboptions(type = "timer")
}
# }