difsm {ptw}R Documentation

Smoothing with a finite difference penalty

Description

This function smoothes signals with a finite difference penalty of order 2.

Usage

difsm(y, lambda)

Arguments

y signal to be smoothed: a vector
lambda smoothing parameter: larger values lead to smoothing

Value

smoothed signal: a vector

Author(s)

Paul Eilers, Jan Gerretzen

References

Eilers, P.H.C. Parametric Time Warping. Anal. Chem., 2004, 76, 404 - 411

Eilers, P.H.C. A perfect smoother. Anal. Chem., 2003, 75, 3631 - 3636

Examples

  data(gaschrom)
  plot(gaschrom[1,], type = "l", ylim = c(0, 100))
  lines(difsm(gaschrom[1,], lambda = 1e5), col = 2)
  lines(difsm(gaschrom[1,], lambda = 1e6), col = 3)
  lines(difsm(gaschrom[1,], lambda = 1e7), col = 4)
  

[Package ptw version 1.0-0 Index]