属性约简(matlab算法)有实例有讲解.doc

文档介绍：粗糙集 属性约简
题目:  SARS 诊断
注：这是我学粗糙集时老师给的作业
 
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属性约简的顺序如下：求正域、生成未经处理的区分矩阵、对区分矩阵进行化简、求核、对已经处理过的区分矩阵进行属性约简。约简后的决策表有26行,所有12个属性都是正域中的属性，核为空
 
程序:
%
tic;
a=[ 1,1,1,1,0,0,0,0,1,1,0,1;
    0,0,0,0,0,0,0,0,0,0,0,0;
    1,0,1,0,0,0,0,0,0,1,0,0;
    0,0,0,1,1,1,1,0,1,0,1,1;
    1,0,0,1,1,1,1,1,0,1,1,0;
    0,1,0,1,1,1,1,1,1,0,0,1;
    1,0,0,0,1,1,1,0,0,1,1,1;
    1,1,1,1,0,0,0,0,1,1,0,1;
    1,0,1,1,1,0,0,0,1,1,0,1;
    1,1,1,1,0,0,0,0,1,1,0,1;
    1,0,1,1,1,0,0,0,1,1,0,1;
    1,0,1,1,1,0,0,0,1,1,0,1 ];
d=[1;0;0;0;0;0;0;1;1;1;1;1];
pos=posCD(a,d);
dismat=dismatrix(a,d,pos);
dism=disbe(dismat);
core=cor(dism);
[red,row]=redu(dism);
time=toc
%
% 生成未经处理的区分矩阵dismat
function dismat=dismatrix(a,d,pos)
[m,n]=size(a);
p=1;
index1=0;index2=0;index=0;
dis=-1*ones(m*(m-1)/2,n);
for i=1:m
    for j=i+1:m
        if (isxbelongtopos(i,pos)&~isxbelongtopos(j,pos))...
                |(~isxbelongtopos(i,pos)&isxbelongtopos(j,pos))...
                |(isxbelongtopos(i,pos)&isxbelongtopos(j,pos)&~isxybelongtoindD(i,j,d))
            index2=1;
        end
        if index2==0
            continue;
        end
        for k=1:n
            if a(i,k)~=a(j,k)
                dis(p,k)=1;
                index1=1;
            else dis(p,k)=0;
            end
        end
        if index1==1
            p=p+1;index=1;
        end