How to change the x increment in xy files?

I have a large number of infrared spectra, essentially xy data, saved as .csv files. The x increment or step for each spectra is different, e.g. one file may be every 0.5 (0, 0.5, 1 etc.) and another file every 0.75 (0, 0.75, 1.5) etc. I wish to restructure such that all data files have the same x increment. Ultimately I'm hoping to run least squares regression analysis between new spectra and the database I hold to find close matches. Could you give me some coding clues, please?

Answer 1

[Ingrid]

just use interp1 to set all data to the same x-vector via linear interpolation. If you have large datasets, you might want to use nakeinterp1 as it is much faster than the built in matlab function ( http://www.mathworks.com/matlabcentral/newsreader/view_thread/258413 )

[Star Strider]

The FEX submission interp1qr is also an option.