ffcsaps {dplR}R Documentation

Smoothing Spline with User-Specified Rigidity and Frequency Cutoff

Description

Applies a smoothing spline to y with rigidity nyrs and a frequency response at a wavelength of f.

Usage

  ffcsaps(y,x=1:length(y),nyrs=length(y)/2,f=0.5)

Arguments

y a vector, typically a tree-ring series.
x a vector with length(y), typically giving the years of y.
nyrs a number giving the rigidity of the spline, defaults to length(y)/2.
f a number between 0 and 1 giving the frequency response or wavelength cutoff.

Details

This applies a smoothing spline similar to the spline applied in most dendrochonological software. See references for more information.

Value

A filtered vector.

Note

DendroLab website: http://dendrolab.org/

Author(s)

Code provided by DendroLab based on work by F. Qeadan, University of Nevada Reno, USA and adapted for dplR by Andy Bunn

References

Cook, E.R. and Kairiukstis, L.A. (1990) Methods of Dendrochronology: Applications in the Environmental Sciences. Springer. ISBN-13: 978-0792305866.

See Also

hanning detrend

Examples


  # Use series CAM011 from the Campito dataset
  data(ca533)
  series = ca533[,"CAM011"]
  series=series[!is.na(series)]
  plot(series,type='l',ylab='Ring Width (mm)',col='grey')
  lines(ffcsaps(series,nyrs=32),col='red',lwd=2)
  lines(ffcsaps(series,nyrs=64),col='green',lwd=2)
  lines(ffcsaps(series,nyrs=128),col='blue',lwd=2)

  # Use first series from the Mesa Verde dataset
  data(co021)
  series = co021[,1] #
  series=series[!is.na(series)]
  plot(series,type='l',ylab='Ring Width (mm)',col='grey')
  lines(ffcsaps(series,nyrs=32),col='red',lwd=2)
  lines(ffcsaps(series,nyrs=64),col='green',lwd=2)
  #nyrs defaults to 0.5*length(series) = 347
  lines(ffcsaps(series),col='blue',lwd=2)

[Package dplR version 1.2.5 Index]