Stepwise variable selection (user contributed).
- channel = calibsel(x,y,alpha,flag)
CALIBSEL performs the variable selection procedure described in Brown, P.J., Spiegelman, C.H., and Denham, M.C., "Chemometrics and spectral frequency selection", Phil. Trans. R. Soc. Land. A 337, 311-322, (1991).
Inputs are the calibration spectra (x) and concentrations (y), significance level for chi-square test (alpha), and a variable (flag) that allows the user to modify how the routine iterates. The output (channel) is a vector of indices corresponding to selected channels/wavelengths in (y).