Wavelength Binning

In order to reduce the spectral resolution and thus gain signal to noise ratio or to reduce the dimensionality of the spectral data set, the spectral resolution can be reduced.

spc.bin(spc, by = stop("reduction factor needed"), na.rm = TRUE, ...)

Arguments

spc	The hyperSpec object.
by	Reduction factor.
na.rm	decides about the treatment of NAs: if FALSE or 0, the binning is done using na.rm = FALSE, if TRUE or 1, the binning is done using na.rm = TRUE, if 2, the binning is done using na.rm = FALSE, and resulting NAs are corrected with mean(..., na.rm = TRUE). See section "Details".
...	Ignored.

Value

A hyperSpec object with ceiling(nwl(spc)/by) data points per spectrum.

Details

The mean of every by data points in the spectra is calculated.

Using na.rm = TRUE always takes about twice as long as na.rm = FALSE.

If the spectra matrix does not contain too many NAs, na.rm = 2 is faster than na.rm = TRUE.

Author

C. Beleites

Examples

spc <- spc.bin(flu, 5)
#> Warning: Last data point averages only 1 point.

plot(flu[1, , 425:475])
plot(spc[1, , 425:475], add = TRUE, col = "blue")

nwl(flu)
#> [1] 181
nwl(spc)
#> [1] 37