resample2 {prospectr} | R Documentation |
Resample a data matrix
, data.frame
or
vector
to match the response of another instrument
using full width half maximum (FWHM) values
resample2(X,wav,new.wav,fwhm)
X |
numeric |
wav |
a numeric |
new.wav |
a numeric |
fwhm |
numeric |
The function uses gaussian models defined by fwhm values to resample the high resolution data to new band positions and resolution. It assumes that band spacing and fwhm of the input data is constant over the spectral range. The interpolated values are set to 0 if input data fall outside by 3 standard deviations of the gaussian densities defined by fwhm.
a matrix
or vector
with resampled values
Antoine Stevens
data(NIRsoil) wav <- as.numeric(colnames(NIRsoil$spc)) spc <- 1/10^NIRsoil$spc # conversion to reflectance # Plot 10 first spectra matplot(wav,t(spc[1:10,]),type='l',xlab='Wavelength /nm',ylab='Reflectance') # ASTER SWIR bands (nm) new.wav <- c(1650,2165,2205,2260,2330,2395) # positions fwhm <- c(100,40,40,50,70,70) # fwhm's # Resample NIRsoil to ASTER band positions aster <- resample2(spc,wav,new.wav,fwhm) matpoints(as.numeric(colnames(aster)),t(aster[1:10,]),pch=1:5)