Apply a function on the spectra of a Spectra* object
Aggregates spectral and data information of a Spectra object using a
user-defined function.
Apply a function and update the spectra of a Spectra object. This
function is particularly interesting for pre-processing, e.g to derive the
spectra, or apply pre-processing functions such as snv.
apply_spectra(obj, fun, ...)
obj |
an object inheriting from class |
fun |
an aggregation function |
... |
expressions evaluated in the context of |
The philosophy of this function is to let the user free to use any function
to pre-process a spectra collection, using either functions from the stats
package, functions from other packages such as signal, or personal
functions.
An object of the same class as obj
Pierre Roudier pierre.roudier@gmail.com
# Loading example data
data(australia)
spectra(australia) <- sr_no ~ ... ~ 350:2500
# Second derivative
r <- apply_spectra(australia, diff, 2)
plot(r)
# Smoothing kernel
k <- kernel("daniell", 20) # define a kernel
r <- apply_spectra(australia, kernapply, k)
plot(r)
## Not run:
# Savitzky-Golay filter (from the signal package)
library(signal)
r <- apply_spectra(australia, sgolayfilt, n = 33, p = 4)
plot(r)
## End(Not run)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.