6- Tucker
Tucker model is an N-way model. For a scientific overview of the method, click here.
Some specifications:

- It allows missing data.

- "Num.factors" is the place where the user puts the N parameters.

The user has to write "-1" when he does not want to reduce the correponding mode (Tucker2/1 ).

- "OK" button executes Tucker model.A default plot is returned after run (unless an information appears). The other plots are available in the menu "results".
- "bootstrap" button excutes Tucker model on original and resampled (by bootstrap) data. The user will obtain the same plot as preceeding, but with a bootstrap estimation of stability of the model (convex hulls, etc...). Available only for 3D!
- "Preprocessing" button opens a new window, see below.
- "Postprocessing" button opens a new window, see below.
- "close" button closes the window.
- Validation window:(Available only for 3D!)The global stability of the model is estimated for different parameters between
  [1 1 1] and "num. factors" number. After having chosen the maximal parameters, the user has to click on the "OK" button. A surface is plotted .

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Submenus and sub-windows:

preprocess menu:

see parafac window.

post-processing window:

Tucker solutions are subspaces:we can choose the basis of these subspaces , in order to have the most interpretable solution. Basis can be found in order to maximise different criteria.

- maximise the diagonale of the core (when the core is cubic)
- maximise the slice-wise diagonale of the core (when the 2 first dimensions of the core are equal.
- maximise thesquared variance of the core.
- No rotation:default, i.e. Singular Value Decomposition of the columns of the loadings.

Tucker options:

It is used to affect parameters of the Tucker algorithm.

Bootstrap options:

- Bootstrap model : naive (resampling the horizontal slabs of X) and residual (resampling the horizontal slabs of the residuals of Tucker(X)).
- Bootstrap replicates: Number of replicates.