calc.zerocoef {ptw} | R Documentation |
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.
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.
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)