calc.zerocoef: Correction for warping coefficients when using zeropadding
In ptw: Parametric Time Warping

Description Usage Arguments Value Author(s) References See Also Examples

This function calculates the warping coefficients for the original range of the data, based on the warping of zero-filled data. Only needed when zeros are added in the beginning of the signal.

1	calc.zerocoef(coef, zeros)

`coef`	vector of warping coefficients of a PTW-calculation on a set of signals with zeros added to the beginning of the signal
`zeros`	the number of zeros added

a vector containing the corrected warping coefficients

Jan Gerretzen

Bloemberg, T.G., et al. (2010) "Improved parametric time warping for Proteomics", Chemometrics and Intelligent Laboratory Systems, 104 (1), 65 – 74.

padzeros calc.multicoef

data(gaschrom)
gaschrom.zf <- padzeros(gaschrom, 250)
ref <- gaschrom[1,]
samp <- gaschrom[16,]
ref.zf <- gaschrom.zf[1,]
samp.zf <- gaschrom.zf[16,]
gaschrom.ptw <- ptw(ref.zf, samp.zf)
layout(matrix(1:2,2,1, byrow=TRUE))
plot(gaschrom.ptw)
corr.coef <- calc.zerocoef(gaschrom.ptw$warp.coef, 250)
gaschrom.ptw2 <- ptw(ref, samp, init.coef = corr.coef, try = TRUE)
plot(gaschrom.ptw2)