Secondary axes for wavelengths

Secondary axes for wavelength data in nanometres. With suitable scaling and name (axis label) for frequency, wave number, photon energy and wavelength.

Usage

sec_axis_w_number(
  unit.exponent = -6,
  label.text = axis_labels(append = ifelse(axis.symbols, ",", ""))[["w.number"]],
  axis.symbols = getOption("ggspectra.axis.symbols", default = TRUE)
)

sec_axis_w_frequency(
  unit.exponent = 12,
  label.text = axis_labels(append = ifelse(axis.symbols, ",", ""))[["freq"]],
  axis.symbols = getOption("ggspectra.axis.symbols", default = TRUE)
)

sec_axis_energy_eV(
  unit.exponent = 0,
  label.text = axis_labels(append = ifelse(axis.symbols, ",", ""))[["energy"]],
  axis.symbols = getOption("ggspectra.axis.symbols", default = TRUE)
)

sec_axis_energy_J(
  unit.exponent = -18,
  label.text = axis_labels(append = ifelse(axis.symbols, ",", ""))[["energy"]],
  axis.symbols = getOption("ggspectra.axis.symbols", default = TRUE)
)

sec_axis_wl(
  unit.exponent = -9,
  label.text = axis_labels(append = ifelse(axis.symbols, ",", ""))[["w.length"]],
  axis.symbols = getOption("ggspectra.axis.symbols", default = TRUE)
)

Arguments

unit.exponent

integer The exponent on base 10 of the scale multiplier used for the axis labels, e.g., 3 for \(10^3\) or \(k\).

label.text

character Textual portion of the labels.

axis.symbols

logical If TRUE symbols of the quantities are added to the name. Supported only by format = "R.expression".

Details

These secondary axis functions can be used only when the x aesthetic is mapped to a numerical variable containing wavelength values expressed in nanometres. They can be used to add a secondary x axis to plots created using ggplot() or autoplot().

See also

the default text used for quantity names are most easily changed by resetting all the defaults once as explained in axis_labels_uk, even if it is possible to override them also in each call.

Examples

ggplot(sun.spct) +
  geom_line() +
  scale_x_wl_continuous(sec.axis = sec_axis_w_number())


# Secondary axes can be added to plots built with autoplot() methods
autoplot(sun.spct) +
  scale_x_wl_continuous(sec.axis = sec_axis_w_number())
#> Scale for x is already present.
#> Adding another scale for x, which will replace the existing scale.


# Using 'ggplot2' scale
ggplot(sun.spct) +
  geom_line() +
  scale_x_continuous(name = w_length_label(),
                     sec.axis = sec_axis_w_number())


# change scale multipliers, SI defined
ggplot(sun.spct) +
  geom_line() +
  scale_x_wl_continuous(-6, sec.axis = sec_axis_w_number(-3))


# change scale multipliers, not SI defined (best avoided)
ggplot(sun.spct) +
  geom_line() +
  scale_x_wl_continuous(-8, sec.axis = sec_axis_w_number(-4))


# Change quantity name to Spanish
ggplot(sun.spct) +
  geom_line() +
  scale_x_wl_continuous(label.text = "Longitud de onda,",
                        sec.axis = sec_axis_w_frequency(label.text = "Frecuencia,"))


# Frequency in secondary axis
ggplot(sun.spct) +
  geom_line() +
  scale_x_wl_continuous(sec.axis = sec_axis_w_frequency())


# Energy (per photon) in atto joules
ggplot(sun.spct) +
  geom_line() +
  scale_x_wl_continuous(sec.axis = sec_axis_energy_J())


# Energy (per photon) in electron volts
ggplot(sun.spct) +
  geom_line() +
  scale_x_wl_continuous(sec.axis = sec_axis_energy_eV())


# Secondary axis with wavelength using a different scale factor
ggplot(sun.spct) +
  geom_line() +
  scale_x_wl_continuous(sec.axis = sec_axis_wl(-6))


# Secondary axes can be added to plots built with autoplot() methods
autoplot(sun.spct) +
  scale_x_wl_continuous(sec.axis = sec_axis_wl(-6))
#> Scale for x is already present.
#> Adding another scale for x, which will replace the existing scale.