stat_wl_strip {ggspectra} | R Documentation |
Calculate colours from wavelength.
Description
stat_wl_strip
computes color definitions according to human vision and
by default plots a narrow, guide-like colour gradient strip based on
wavelength. x
-scale transformations and axis flipping are
currently not supported.
Usage
stat_wl_strip(
mapping = NULL,
data = NULL,
geom = "rect",
position = "identity",
...,
by.group = FALSE,
w.band = NULL,
length.out = 150,
chroma.type = "CMF",
na.rm = TRUE,
show.legend = FALSE,
inherit.aes = TRUE
)
wl_guide(
mapping = NULL,
data = NULL,
position = "identity",
...,
by.group = FALSE,
chroma.type = "CMF",
w.band = NULL,
length.out = 150,
ymin = -Inf,
ymax = Inf,
na.rm = FALSE,
show.legend = FALSE,
inherit.aes = TRUE
)
Arguments
mapping |
The aesthetic mapping, usually constructed with
|
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 |
by.group |
logical flag If TRUE repeated identical layers are added
for each group within a plot panel as needed for animation. If
|
w.band |
waveband object or a list of such objects or NULL. |
length.out |
The number of steps to use to simulate a continuous range of colours when w.band == NULL. |
chroma.type |
character one of "CMF" (color matching function) or "CC"
(color coordinates) or a |
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?
|
inherit.aes |
If |
ymin , ymax |
numeric used as aesthetics for plotting the guide. |
Details
By default stat_wl_strip()
uses a panel function and ignores
grouping as needed for annotation of layers supporting free axis scales.
Passing by.group = TRUE
as argument changes this behaviour adding
the same layer repeatedly for each group as needed for constructing
animated plots with functions from package 'gganimate'.
Function wl_guide()
is a conveneince wrapper on
stat_wl_strip()
that also adds the required
scale_fill_identity()
.
As colours are returned as RGB colour definitions, depending on the
geometry used the use of scale_fill_identity
and/or scale_colour_identity
will be necessary for
the correct colours to be displayed in the plot.
Value
generic_spect object with new x
values plus other computed
variables described below.
Computed variables
- x
(w.low + wl.high) / 2
- wl.low
boundary of waveband
- wl.high
boundary of waveband
- wl.color
color corresponding to wavelength
- wb.color
color corresponding to waveband
- wb.name
label of w.band
Default aesthetics
Set by the statistic and available to geoms.
- x
..x..
- label
as.character(..wb.f..)
- xmin
..wl.low..
- xmax
..wl.high..
- fill
..wb.color..
Required aesthetics
Required by the statistic and need to be set with aes()
.
- x
numeric, wavelength in nanometres
Note
As only one colour scale can exist within a "gg"
object, using
this scale prevents the mapping to the colour aesthetic of
factors in data
to create a grouping.
See Also
color_of
and
fast_color_of_wl
, which are used in the
implementation.
Other stats functions:
stat_color()
,
stat_find_qtys()
,
stat_find_wls()
,
stat_label_peaks()
,
stat_peaks()
,
stat_spikes()
,
stat_wb_box()
,
stat_wb_column()
,
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_summary()
Examples
# ggplot() methods for spectral objects set a default mapping for x and y.
ggplot(sun.spct) +
geom_line() +
stat_wl_strip(ymax = -0.02, ymin = -0.04) +
scale_fill_identity()
# on some graphic devices the output may show spurious vertical lines
ggplot(sun.spct) +
wl_guide(alpha = 0.33, color = NA) +
geom_line()