feemgrid {albatross} | R Documentation |
Interpolate FEEMs on a given wavelength grid
Description
Use interpolation to change the wavelength grid of a single FEEM or unify the grid of a collection of them.
Usage
feemgrid(x, ...)
## S3 method for class 'feem'
feemgrid(
x, emission, excitation,
method = c("whittaker", "loess", "kriging", "pchip"), ...
)
## S3 method for class 'feemcube'
feemgrid(
x, emission, excitation, ..., progress = TRUE
)
## S3 method for class 'list'
feemgrid(
x, emission, excitation, ..., progress = TRUE
)
Arguments
x |
|
emission , excitation |
Desired wavelength grid, as numeric vectors. Must be specified for a single FEEM. If not specified for a collection of FEEMs, all wavelengths falling in the range of the intersection all wavelengths intervals are chosen. |
method |
Interpolation method, see |
... |
Passed from generics to |
progress |
Set to |
Details
The algorithm doesn't know how to distinguish between NA
s
that haven't been measured and NA
s that resulted from
combining different wavelength grids, so it tries to interpolate all
of them. As a result, leaving large areas of the spectrum undefined
(e.g. anti-Stokes area) is not recommended, since it would result in
extrapolation and introduce strong artefacts.
Value
An object of the same kind (FEEM object / FEEM cube / list of them) with emission and excitation wavelengths as requested.
See Also
Examples
data(feems)
x <- feemscatter(feems$a, rep(25, 4))
y <- feemgrid(x, seq(240, 600, 5), seq(230, 550, 10))
plot(plot(x, main = 'Original' ), split = c(1, 1, 2, 1), more = TRUE)
plot(plot(y, main = 'Interpolated'), split = c(2, 1, 2, 1))