SPIDER The Spider Objects

Mapping object

   A=MAP(H) returns a map object initialized with hyperparameters H. 
    MAP is a general object for mapping data, it takes a supplied
    mapping function which can transform the given input data. The 
    function can use four hyperparmeters p1,p2,p3,p4.
    Hyperparameters, and their defaults
     func='d.X=tanh((d.X+a.p1)*a.p2)' -- function we wish to use.
                                       This can be changed at will,
                                       it can access the object 'd' (data)
                                       and 'a' (mapping algorithm), e.g
                                       d.X, d.Y, a.p1, a.p2, etc. and 
                                       usual matlab functions. It should 
                                       store the new values in d.X. 
                                        The default is a sigmoid mapping.
     p1=1,p2=0,p3=[],p4=[]          -- user parameters