Thank you all for your sensible advice and references. I'm going to test on my 
data the different clustering methods / softwares you suggested to me.
Just one last thing, it seems that all these methods but the k-modes one are 
included either in SPSS or R or LCA software, all available from the WEB ; could 
you indicate me an available program / library (fortran, matlab, etc) that 
includes the k-modes method so that I can also test it in parallel with the 
other methods ?

Best Regards,


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