wl {hyperSpec}

Getting and Setting the Wavelength Axis wl returns the wavelength axis, wl<- sets it.

Description

The wavelength axis of a hyperSpec object can be retrieved and replaced with wl and wl<-, respectively.

Usage

wl(x)

wl (x, label=NULL, digits=6) <- value

Arguments

x

a hyperSpec object

label

The label for the new wavelength axis. See initialize for details.

digits

handed to signif. See details.

value

either a numeric containing the new wavelength vector, or a list with value$wl containing the new wavelength vector and value$label holding the corresponding label.

Details

When the wavelength axis is replaced, the colnames of x@data$spc are replaced by the rounded new wavelengths. digits specifies the how many significant digits should be used.

There are two ways to set the label of the new wavelength axis, see the examples. If no label is given, a warning will be issued.

Value

a numeric vector

hyperSpec object

Note

wl<- always sets the complete wavelength axis, without changing the columns of the spectra matrix. If you rather want to cut the spectral range, use [, for interpolation along the spectral axis see spc.loess and for spectral binning spc.bin.

Author(s)

C. Beleites

See Also

signif

cutting the spectral range: [

interpolation along the spectral axis: spc.loess

spectral binning: spc.bin

Examples

	wl (laser)

	# convert from wavelength to frequency
	plot (laser)
	wl (laser, "f / Hz") <- 2.998e8 * wl (laser) * 1e9
	plot (laser)

	# convert from Raman shift to wavelength
	# excitation was at 785 nm
	plot (chondro [1])
	wl (chondro) <- list (wl = 1e7 / (1e7/785 - wl (chondro)), label = expression (lambda / nm))
	plot (chondro [1])