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External parameter orthogonalization

umeshach's picture

Dear All,
I am a new learner in this NIR field. I am doing an experiment on comparison of different ways or methods of temperature compensaiton on fruit dry matter prediction. I collected spectra of fruit at three temperature 15, 25 and 35 degree and developed calibration models with individual temperature and combining all temp. Later I used these models to predict an independent population at 35 degree. I am using short wave region 720-950 nm with second derivative of absorbance data taken in interactance mode. My interest is to compare the external parameter orthogonalization method (EPO) with others. As I mostly rely on Unscrambler and don't know about Matlab, Could I get  help from this forum regarding a simplified version of EPO algorithm so that I could use it in a spread sheet before doing analysis using unscrambler software.
Kind regards,

rogerjm's picture

Dear Umesh,
it is not possible to run a simplified version of EPO under excel, because it is based on matrix computation. You could try free softwares as scilab or octave. Using these softwares, EPO implementation is very easy (2 or 3 lines).
I could help you to write these lines

JM Roger
Irstea, Montpellier France

Central Queensland University's picture

Dear Jean-Michel,
Thanks for your answer. It would be great o get those command line from you. As you recommended I am looking for the free software octave/scilab.
Kind regards
Umesh Acharya
CQUniversity, Rockhampton, Australia