[!] Isometric planar transformation

Compute the isometric planar transform of a (dataset of) composition(s). Default method is function ipt from package compositions.

ipt(x, V = ilrBase(x), ...)

# S3 method for default
ipt(x, V = ilrBase(x), ...)

# S3 method for hyperSpec
ipt(x, V = ilrBase(x), ...)

Arguments

x

A composition, not necessarily closed. (A numeric data frame or matrix.)

...

further parameters to ipt.

Value

Returns the transformed data matrix with one dimension less than

x. Thus for hyperSpec object the last value of

x$.wavelength is removed.

See also

ipt, ilrBase

Other row-wise transformations: alr(), apt(), clr(), cpt(), ilr()

Examples

ipt(Spectra2)
#> hyperSpec object
#>    150 spectra
#>    3 data columns
#>    500 data points / spectrum

plot(Spectra2)

plot(ipt(Spectra2))