How do I add data from FTIR spectra that have been exported as CSV file into any program such as MATLAB/SPSS/SIMCA/UNSCRAMBLER to run for PCA.
I have performed all pre-processing methods including first-order derivation, but when inserted into SPSS for PCA, the data appears only as one component.
I have a total of 22 samples with spectra ranging from 650-3300 (meaning I have total of over 2700 data points per sample) but still appears as only one component.
I have searched many articles on chemometrics but all does not include a detailed step-by-step procedure.
What did I miss or where did I go wrong?
to perform PCA your data should be collected in matrix [22, 2700] then 22 components should be calculated by PCA. When you get only one component then all spectra could have the same shape. Loadings for first component describe this shape and scores show changes in intensity
To read CSV files, please see...
www.mathworks.co.uk/help/matlab/ref/csvread.html
The command is...
M = csvread(filename) % reads a comma-separated value (CSV) formatted file into array M. The file must contain only numeric values.
Then, you you want to do PCA you need to study PCA to do it properly. Read what Andrzej Grabowski (above) just said too.
Have fun!
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