| normalized_diff_ind {photobiology} | R Documentation |
This function returns a normalized difference index value for an arbitrary pair of wavebands.
normalized_diff_ind(spct, plus.w.band, minus.w.band, f, ...)
spct |
an R object |
plus.w.band |
waveband objects The waveband determine the region of the spectrum used in the calculations |
minus.w.band |
waveband objects The waveband determine the region of the spectrum used in the calculations |
f |
function used for integration taking spct as first argument and a list of wavebands as second argument. |
... |
additional arguments passed to f |
A numeric value for the index
f is most frequently reflectance, but also
transmittance, or even absorbance,
response, irradiance or a user-defined function
can be used if there is a good reason for it. In every case spct
should be of the class expected by f. When using two wavebands of
different widths do consider passing to f a suitable quantity
argument. Wavebands can describe weighting functions if desired.