Table 1 The calculation and use of four types of R-Correlation

R1: R(f _i ,C)

SU _i,C

\(\{\Omega _{k}\},M_{s},G\! \subseteq \!\cup _{u}{M_{s}^{p}}[\!u]\)

ε-Estimation

R2: R(f _ij ,C)

SU _i,j;C

Strongly Relevant f _ij

ε-Estimation

R3: R(f _i ,f _j )

SU _i,j

ε-Estimation

R4: R(f _i ,C|M _s )

CMI (f _i ,C|M _s )

Feature Redundancy