spectrolab (version 0.0.18)

plot_regions: Plot polygons for spectral regions

Description

plot_regions plots polygons for default (VIS, NIR, SWIR 1, SWIR 2) or customized regions of the spectrum.

Usage

plot_regions(
  spec,
  regions = default_spec_regions(),
  col = grDevices::rgb(0.7, 0.7, 0.7, 0.3),
  border = FALSE,
  add = TRUE,
  add_label = TRUE,
  cex_label = 1,
  ...
)

Value

nothing. Called for its side effect.

Arguments

spec

spectra object

regions

matrix with spectral regions in columns and only two rows named "begin" and "end". Values are the bands where a spectral regions begins and ends. See details for how the default regions are defined.

col

color for regions. Single value or vector of length ncol (regions).

border

color for region borders. Defaults to FALSE (no border).

add

boolean. If TRUE (default) adds polygons to current plot (if a plot exists) or throws an error if a plot does not exist. If FALSE, a new plot is created **without** any spectra.

add_label

boolean. Add region column names on top of the polygons?

cex_label

label scale

...

additional parameters passed to polygon().

Author

Jose Eduardo Meireles

Details

Default regions: spec_regions = cbind("VIS" = c(begin = 400, end = 700), "NIR" = c(begin = 800, end = 1300), "SWIR1" = c(begin = 1550, end = 1800), "SWIR2" = c(begin = 2000, end = 2400)).

Examples

library(spectrolab)
spec = as_spectra(spec_matrix_example, name_idx = 1)
plot_regions(spec, default_spec_regions())
plot(spec, add = TRUE)

# Alternatively, if you want to get fancy...
if (FALSE) {
col_fun = colorRampPalette(c(rgb(1, 1, 0, 0.7),rgb(1, 0, 0, 0.7)), alpha = TRUE)
colors = col_fun(4)

plot_regions(spec,default_spec_regions(), col = colors)
plot(spec, add = TRUE)
}