Positive Macroscopic Approximation for Fast Attribute Reduction

Algorithm 1

Quick reduct.

Inputs:

𝑈: the universe

𝐶: 𝐶={𝑐₁,𝑐₂,…,𝑐_𝑛}, a condition attribute set

𝐷: 𝐷={𝑑}, a decision attribute set

Output:

red: a reduct of 𝐶

Begin

Step  1.  Let red=∅ and 𝑅=𝐶

Step  2.  While 𝛾_red(𝐷)≠𝛾_𝐶(𝐷) and 𝑅≠∅ do

     Select an attribute 𝑎∈𝑅 with Sig(𝑎,red,𝐷)=max(Sig(𝑎,red,𝐷)) where 𝑎_𝑖∈𝑅

     𝑅=𝑅−{𝑎}

     red=red∪{𝑎}

Step  3. Output red

End.