CMAPM

Compute some special maps

  INPUT
   Various

Output
W	Mapping

Description

CMAPM computes some special data-independent maps for scaling, selecting or  rotating K-dimensional feature spaces.

    W = CMAPM(K,N)            Selects the features listed in the vector N
    W = CMAPM(K,P)            Polynomial feature map. P should be an N*K matrix
                              in which each row defines the exponents for the
                              original features in a polynomial term. Note: for
                              N = 1 and/or K = 1, feature selection is applied!
    W = CMAPM(K,'EXP')        Exponential, negative exponential and logarithmic 
    W = CMAPM(K,'NEXP')       mappings.
   W = CMAPM(K,'LOG')
   W = CMAPM(K,'RANDROT') Defines a random K-dimensional rotation.
   W = CMAPM(F,'ROT') The N*K matrix F defines N linear combinations
                             to be computed by X*F'.
   W = CMAPM(X,'SHIFT') Defines a shift of the origin by X.
   W = CMAPM(S,'SCALE') Divides the features by the components of the
                             vector S.
   W = CMAPM({X,S},'SCALE') Shift by X and scale by S.

Example(s)

 For the polynomial feature map, CMAPM(K,P), P defines exponents for each
 feature. So P = [1 0; 0 1; 1 1; 2 0; 0 2; 3 0; 0 3] defines 7 features,
 the original 2 (e.g. x and y), a mixture (xy) and all powers of the second
 (x^2,y^2) and third (x^3,y^3) order. Another example is P = diag([0.5 0.5
 0.5]), defining 3 features to be the square roots of the original ones.

See also

mappings, scalem, featselm, klm,