plot.cube: Plot a gdalcubes data cube

Description Usage Arguments Details Note Examples

View source: R/plot.R

Description

Plot a gdalcubes data cube

Usage

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## S3 method for class 'cube'
plot(
  x,
  y,
  ...,
  nbreaks = 11,
  breaks = NULL,
  col = grey(1:(nbreaks - 1)/nbreaks),
  key.pos = NULL,
  bands = NULL,
  t = NULL,
  rgb = NULL,
  zlim = NULL,
  periods.in.title = TRUE,
  join.timeseries = FALSE,
  axes = TRUE,
  ncol = NULL,
  nrow = NULL,
  na.color = "#AAAAAA"
)

Arguments

x

a data cube proxy object (class cube)

y

__not used__

...

further arguments passed to image.default

nbreaks

number of breaks, should be one more than the number of colors given

breaks

actual breaks used to assign colors to values; if missing, the function subsamples values and uses equally sized intervals between min and max or zlim[0] and zlim[1] if defined

col

color definition, can be a character vector with nbreaks - 1 elements or a function such as heat.colors

key.pos

position for the legend, 1 (bottom), 2 (left), 3 (top), or 4 (right). If NULL (the default), do not plot a legend.

bands

integer vector with band numbers to plot (this must be band numbers, not band names)

t

integer vector with time indexes to plot (this must be time indexes, not date / time)

rgb

bands used to assign RGB color channels, vector of length 3 (this must be band numbers, not band names)

zlim

vector of length 2, defining the minimum and maximum values to either derive breaks, or define black and white values in RGB plots

periods.in.title

logical value, if TRUE, the title of plots includes the datetime period length as ISO 8601 string

join.timeseries

logical, for pure time-series plots, shall time series of multiple bands be plotted in a single plot (with different colors)?

axes

logical, if TRUE, plots include axes

ncol

number of columns for arranging plots with layout(), see Details

nrow

number of rows for arranging plots with layout(), see Details

na.color

color used to plot NA pixels

Details

The style of the plot depends on provided parameters and on the shape of the cube, i.e., whether it is a pure time series and whether it contains multiple bands or not. Multi-band, multi-temporal images will be arranged with layout() such that bands are represented by the x axis and time is represented by the y axis. Time series plots can be combined to a single plot by setting join.timeseries = TRUE. For other cases, a default arrangement of the plots is derived, trying to reach a square overall plot. The layout can be controlled with ncol and nrow, which define the number of rows and columns in the plot layout. Typically, only one of ncol and nrow is provided. For multi-band, multi-temporal plots, the actual number of rows or columns can be less if the input cube has less bands or time slices.

Note

If caching is enabled for the package (see gdalcubes_options), repeated calls of plot for the same data cube will not reevaluate the cube. Instead, the temporary result file will be reused, if possible.

Some parts of the function have been copied from the stars package (c) Edzer Pebesma

Examples

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# 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")) 
}

L8.col = image_collection(file.path(tempdir(), "L8.db"))
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="P1M")
              
plot(select_bands(raster_cube(L8.col, v), c("B02", "B03", "B04")), rgb=3:1)
              
L8.cube = select_bands(raster_cube(L8.col, v), c("B04", "B05")) 
L8.ndvi = apply_pixel(L8.cube, "(B05-B04)/(B05+B04)", "NDVI") 
plot(reduce_time(L8.ndvi, "median(NDVI)"), key.pos=1, zlim=c(0,1))

gdalcubes documentation built on Oct. 28, 2021, 5:06 p.m.