Classifion is a freeware chemometrics software for classification of
substances using their mass-spectra. The used multivariate analysis is
based on Principal Component Analysis with Mahalanobis Distance (PCA-MD)
and it is of one class classifier category. Classifion has been
tested using mass-spectra, but there is no limitation to be used with
any other kind of characteristic spectra (e.g. VIS, IR, NMR). The only
twist is to find appropriate channel (bin) size, which in case of
mass-spec is naturally the mass number.
Where does it sit...
Almost every mass-spectrometry lab is equipped with spectral-library
search program with tens of thousands of spectra of pure compounds. The
problems begin when you have very complex substances or using mass-spec
methods different from those used in the spec-libraries. In some cases
you don't need to know what exactly is in the sample, but simply does it
belong to a class of samples you already measured. In all these cases
you need to use classification software. But most of them are general
purposed and require certain knowledge of the statistical methods used.
Here Classifion sits, offering you a classification with
specialized for mass-spectrometry environment and automation allowing
you to "avoid the depths of contemporary statistics", so you can
concentrate on your immediate work.
How does it work...
Classifion needs to be "trained" using several measured spectra per
substance. The "training" itself could be conducted automatically or
manually (supervised). The aim of the training is to extract substance
specific information based on statistical characteristics, not the
interpretation of the mass-spectra. Having some knowledge on the
mass-spectra structure could improve classification precision, but it is
not a requirement. Mathematically speaking the extraction is down to
reducing the dimensionality of the spectra variable space (to each mass
corresponds one dimension). PCA is well-known such technique, which
offers other advantages as ordering the principal component by
"significance" (useful for noise reduction).
Classifion can train itself entirely on autopilot.
Just import your data, run Autopilot, sit back and enjoy the view. The
results will show you how successful the training was, so in case of
problem you should re-examine your data or do supervised training.
The feature which makes Classifion better than the
most of PCA software out there, is the use of proper factor space for
each substance separately, instead of traditional approach of using
common factor space for all substances. That improves the classification
precision and makes the work with Classifion similar to the
spectral-library search software.
Classifion can be
controlled remotely from another application (as COM server) combining
remote with user access (see Client.zip
Classifion is using R project software as a statistical calculation
Project for Statistical Computing is
very powerful and yet free software, with thousands of contributors from
all fields of science. So for any R stats or math a front-end (GUI) can
be created as it has been done with Classifion.