> The Spider Objects

>            FSV object

>        A=FSV(H) returns a fsv object initialized with hyperparameters H.

>        Hyperparameters, and their defaults
>         lambda=1             -- the lambda parameter beteen 0 and 1.
>                                 (1=min. zero norm, 0=min. hinge loss)
>         alpha=5              -- the alpha parameter
>         feat=[]              -- number of desired features (if empty gives
>       `                         the smallest)
>         output_rank=0        -- when set to 1, output features only

>        Model
>         rank                 -- the rank of the features
>         w                    -- the weight
>         b0                   -- the threshold

>        Methods:
>         training, testing

>        Example:
>        d=gen(toy); a=fsv; a.feat=10; a.output_rank=1;[r,a]=train(a,d);
>        a.rank    - lists the chosen features in  order of importance

> | Reference : Feature selection via concave minimization and support vector machines

> | Author : Paul S. Bradley and Olvi L. Mangasarian

> | Link : http://portal.acm.org/citation.cfm?id=657467&dl=ACM&coll=GUIDE