Function evaluation on hyperSpec objects.

Source: R/vandermonde.R

vandermonde() generates Vandermonde matrices, the hyperSpec method generates a hyperSpec object containing the van der Monde matrix of the wavelengths of a hyperSpec object.

vanderMonde(x, order, ...)

# S4 method for hyperSpec
vanderMonde(x, order, ..., normalize.wl = normalize01)

Arguments

x

object to evaluate the polynomial on
order

of the polynomial
...

hyperSpec method: further arguments to decomposition()
normalize.wl

function to transorm the wavelengths before evaluating the polynomial (or other function). normalize01() maps the wavelength range to the interval [0, 1]. Use base::I() to turn off.

Value

Vandermonde matrix

hyperSpec method: hyperSpec object containing van der Monde matrix as spectra and an additional column `$.vdm.order$ giving the order of each spectrum (term).

Details

It is often numerically preferrable to map wl(x) to [0, 1], see the example.

See also

wl.eval() for calculating arbitrary functions of the wavelength,

normalize01()

Author

C. Beleites

Examples

plot(vanderMonde(flu, 2))
plot(vanderMonde(flu, 2, normalize.wl = I))