CAT2REAL

Convert categorical features to real features by one-hot encoding

    B = CAT2REAL(A)
    B = A*CAT2REAL

Input
A	Dataset

Output
B	Dataset

Description

Categorical features with N > 2 categories are split in N real features,  one for each category. If the category is set for an object, the real  feature value gets a value sqrt(2)/2. The distance contribution for two  objects with different category values is thereby 1. Features with two  categories are transformed in binary (0/1) features, also contributing  with 1 to object distances for objects with a different feature value.

Missing values in categorical features of A will result in a NaN for all  corresponding features of B. They may be set by MISVAL.

See also

datasets, mappings, setfeatdom, cat2dset, cat2feat, misval,