rsattributereduction.m

matlab粗糙集属性约简程序

%Rough Set Attribute's Reduction algorithm
%Version 1.0  16-July-2008
%Department of Business Management
%NorthChina Electric Power University,Beijing,China
%MicroArmy
%Inputs:
%	AttriValues		    -Attributes' Value matrix
%	DecisionTypeValue	-DecisionTypeValue matrix
%Outputs:
%The Core of the attribute
%0 express can be deleted
%1 express not
%function RSAttributeReduction(AttributeValues,DecisionValues)

function RSAR=RSAttributeReduction(AttributeValues,DecisionValues)
%The Idea of algorithm
%for every attributes,
%deleted one by one, and check the attributevalues
%if(AttributeValues are all different)
%   the deleted attributes can be deleted
%else
%   if(the same AttributeValues' DecisionValues is also same)
%       the deleted attributes can be deleted
%   else
%       the deleted attribute can't be deleted

[m,n]=size(AttributeValues);
record=zeros(n,1);          %Record the attributes weather can be reduced, 0 express can reduced, otherwise is 1;
reducerecord=ones(n,1);    %Record the reduce attribute traces

for j=1:n
    tempAttriV=AttributeValues;
    tempAttriV(:,j)=[];
    if (min(reducerecord)~=1)
        g=0;
        for k=1:j-1
            if (reducerecord(k)==0)
                tempAttriV(:,k-g)=[];
                g=g+1;  %Record the reduce cols
            end
        end
    end
    for i=1:m
        %tempDValues=DecisionValues;
        %tempDValues(i)=[];
        compareResult=Compare(tempAttriV(i,:),tempAttriV,DecisionValues(i),DecisionValues);
        if (compareResult==0)
            record(j)=0;
            reducerecord(j)=0;
        else
            record(j)=1;
            reducerecord(j)=1;
            break
        end
    end
end

%display the result
if(min(reducerecord==0))
    disp('the last column left!')
else
    RSAR=record;
end


function [compareResult]=Compare(RowArray,Matrix,DValue,DArray)
%Input:
%   RowArray:compared array
%   Matrix:the Matrix
%   DValue: the respectivly decision value of the RowArray
%   DArray: the Decision Array
[m1,n1]=size(Matrix);
record1=zeros(m1,n1);       %Record every rows' result of comparing the rowarray with the matrix
samerow=ones(1,n1);         %if attribute row is same ,then produce a onesrow;
compareResult=0;
tempcompareResult=0;
for i1=1:m1
    record1(i1,:)=(RowArray==Matrix(i1,:));
end
for i3=1:m1
    if ((record1(i3,:)==samerow) & (DArray(i3)==DValue))
        compareResult=compareResult | 0;
    elseif ((record1(i3,:)==samerow) & (DArray(i3)~=DValue))
        compareResult=1;
        break
    end
end