corects from sharp baseline shifts, typically observed when lamps are switched
xcorr = gapremove(x,list,window);
a dataset of spectra
spectra are rows in a matrix or in a Div structure
the indexes of the variables on the left side of a correction; for example, if shifts are observed between variables 53 and 54, then between 127 and 128, then between 456 and 457, list shoud contain: [53 127 456]
the number of values used for the slope calculation.