addcp: Manually add fix point to continuum line

addcpR Documentation

Manually add fix point to continuum line


This function is used to add an additional fix point to a manually created hull of a single spectrum. This fix point is then used to re-construct a continuum line.


addcp(x, ispec, cpadd) 



Object of class Clman.


ID or index of spectrum to be modified.


Single value or vector of wavelength containing new fix point(s).


In some cases, it might be desirable to manually adapt automatically constructed segmended hulls (transformSpeclib). For example local maxima could be removed because they are very small and maybe afflicted with uncertainties which might legitimate it to manipulate the continuum line. Therefore, hsdar provides functions to remove and add "continuum points" from or to a continuum line. Manually adapted continuum lines can then be used to update band depth or ratio transformation. Handle these functions with care to avoid continuum lines too much build by subjective decisions. In the typical workflow, spectra are first transformed (transformSpeclib). Continuum points can then be retrieved (getcp) and manually adapted by adding addcp and deleting (deletecp) of points. Use checkhull to check for errors. If all uncertainties are removed, re-calculate the hull (makehull) and update the transformed spectrum (updatecl).


Object of class Clman containing the updated version of x.


Lukas Lehnert and Hanna Meyer

See Also

transformSpeclib, deletecp, getcp, checkhull, makehull, updatecl,



## Model spectra using PROSAIL
parameter <- data.frame(N =, 1.5),2), LAI = c(1,1,3,3))
spec <- PROSAIL(parameterList=parameter)

## Transform spectra
spec_clman <- transformSpeclib(spec, method = "sh", out = "raw")

## Plot original line
par(mfrow = c(1,2))
plot(spec_clman, ispec = 1, xlim = c(2480, 2500), ylim=c(0.022,0.024))

## Add fix point at 4595 nm to continuum line of first spectrum
spec_clman <- addcp(spec_clman, 1, 2495)

## Plot new line
plot(spec_clman, ispec = 1, xlim = c(2480, 2500), ylim=c(0.022,0.024))

## Check new hull
hull <- checkhull(spec_clman, 1)

hsdar documentation built on March 18, 2022, 6:35 p.m.