stat_wb_column: Integrate ranges under curve.

In ggspectra: Extensions to 'ggplot2' for Radiation Spectra

Integrate ranges under curve.

Description

stat_wb_column computes means under a curve. It first integrates the area under a spectral curve and also the mean expressed per nanaometre of wavelength for each waveband in the input. Sets suitable default aesthetics for geom_rect(). x-scale transformations and axis flipping are currently not supported.

Usage

stat_wb_column(
  mapping = NULL,
  data = NULL,
  geom = "rect",
  position = "identity",
  ...,
  w.band = NULL,
  integral.fun = integrate_xy,
  chroma.type = "CMF",
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE
)

Arguments

mapping	The aesthetic mapping, usually constructed with aes or aes_. Only needs to be set at the layer level if you are overriding the plot defaults.
data	A layer specific dataset - only needed if you want to override the plot defaults.
geom	The geometric object to use display the data
position	The position adjustment to use for overlapping points on this layer
...	other arguments passed on to layer. This can include aesthetics whose values you want to set, not map. See layer for more details.
w.band	a waveband object or a list of waveband objects or numeric vector of at least length two.
integral.fun	function on $x$ and $y$.
chroma.type	character one of "CMF" (color matching function) or "CC" (color coordinates) or a chroma_spct object.
na.rm	a logical value indicating whether NA values should be stripped before the computation proceeds.
show.legend	logical. Should this layer be included in the legends? NA, the default, includes if any aesthetics are mapped. FALSE never includes, and TRUE always includes.
inherit.aes	If FALSE, overrides the default aesthetics, rather than combining with them. This is most useful for helper functions that define both data and aesthetics and shouldn't inherit behaviour from the default plot specification, e.g. borders.

Value

A data frame with one row for each waveband object in the argument to w.band. Wavebeand outside the range of the spectral data are trimmed or discarded.

Computed variables

What it is named integral below is the result of appying integral.fun, with default integrate_xy.

x

w.band-midpoint

wb.xmin

w.band minimum

wb.xmax

w.band maximum

wb.ymin

data$y minimum

wb.ymax

data$y maximum

wb.ymean

yint divided by wl_expanse(w.band)

y

wb.ymeam

wb.color

color of the w.band

wb.name

label of w.band

BW.color

black_or_white(wb.color)

Default aesthetics

Set by the statistic and available to geoms.

xmin

..wb.xmin..

xmax

..wb.xmax..

ymin

0

ymax

..wb.ymean..

fill

..wb.color..

Required aesthetics

Required by the statistic and need to be set with aes().

x

numeric, wavelength in nanometres

y

numeric, a spectral quantity

Note

If the argument passed to w.band is a BSWF it is silently converted to a wavelength range and the average of spectral values without weighting is returned as default value for ymax while the default value for ymin is zero.

See Also

Other stats functions: stat_color(), stat_find_qtys(), stat_find_wls(), stat_label_peaks(), stat_peaks(), stat_spikes(), stat_wb_box(), stat_wb_contribution(), stat_wb_hbar(), stat_wb_irrad(), stat_wb_label(), stat_wb_mean(), stat_wb_relative(), stat_wb_sirrad(), stat_wb_total(), stat_wl_strip(), stat_wl_summary()

Examples

library(photobiologyWavebands)
# ggplot() methods for spectral objects set a default mapping for x and y.
ggplot(sun.spct) +
  stat_wb_column(w.band = VIS_bands()) +
  geom_line() +
  scale_fill_identity()

ggplot(sun.spct) +
  stat_wb_column(w.band = VIS_bands(), alpha = 0.5) +
  geom_line() +
  scale_fill_identity()

ggspectra documentation built on April 4, 2025, 2:19 a.m.