属性约简MATLAB算法有实例有讲解

1、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呼吸困难血液检测38肌肉酸痛101112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26行，所有12个属性都是正域中已经处理过的区分矩阵进行属性约简。约简后的决策表有的属性，核为空程序：%main.mtic;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;

2、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%dismatrix.m%生成未经处理白区分矩阵dism

3、atfunctiondismat=dismatrix(a,d,pos)m,n=size(a);p=1;index1=0;index2=0;index=0;dis=-1*ones(m*(m-1)/2,n);fori=1:mforj=i+1:mif(isxbelongtopos(i,pos)&isxbelongtopos(j,pos).|(isxbelongtopos(i,pos)&isxbelongtopos(j,pos).|(isxbelongtopos(i,pos)&isxbelongtopos(j,pos)&isxybelongtoindD(i,j,d)in

4、dex2=1;endifindex2=0continue;endfork=1:nifa(i,k)=a(j,k)dis(p,k)=1;index1=1;elsedis(p,k)=0;endendifindex1=1p=p+1;index=1;endindex1=0;index2=0;endendifp<=m*(m-1)/2ifindex=0dismat=;return;endifdis(p,1)=-1p=p-1;endelsep=m*(m-1)/2;enddismat=dis(1:p,:);%redu.m%对已经处理过的区分矩阵进行知识约简functionred,row=redu(dism

5、)m,n=size(dism);red=;row=0;ifm<=0return;endfori=1:nifdism(1,i)=0row=row+1;endendred(1:row,:)=zeros(row,n);j=1;fori=1:rowwhiledism(1,j)=0j=j+1;endred(i,j)=1;j=j+1;endtemp=;tempdis=;rowd=0;rowd1=0;fori=2:mj=1;whilej<=rowtemp=uni(dism(i,:),red(j,:);s,n=size(temp);rowd1=rowd+s;tempdis(rowd+1:rowd1

6、,:)=temp;rowd=rowd1;j=j+1;temp=;endred=;red=disbe(tempdis);tempdis=;row,n=size(red);rowd=0;rowd1=0;end%disbe.m%对区分矩阵或者约简矩阵进行化简即去掉包含关系functiondism=disbe(dis)m,n=size(dis);p=m;fori=1:mifdis(i,1)=-1forj=1:mifi=j&dis(j,1)=-1ifdis(i,:)<=dis(j,:)dis(j,1)=-1;P=p-1;elseifdis(i,:)>=dis(j,:)dis(i,:)

7、=dis(j,:);dis(j,1)=-1;P=p-1;endendendendenddism=ones(p,n);j=1;fori=1:pwhilej<=m&dis(j,1)=-1j=j+1;enddism(i,:)=dis(j,:);j=j+1;end%posCD.m%a为条件属性矩阵，d为决策属性向量%pos为正域，保存条件属性矩阵的索引值functionpos=posCD(a,d)m,n=size(a);p=m;index=0;fori=1:mifa(i,1)=-1forj=i+1:mifa(j,1)=-1&(a(i,:)=a(j,:)&d(i)=d(j)

8、a(j,1)=-1;p=p-1;index=1;endendifindex=1a(i,1)=-1;p=p-1;index=0;endendendpos=zeros(p,1);i=1;forr=1:pwhilea(i,1)=-1&i<=mi=i+1;endpos(r)=i;r=r+1;i=i+1;end%cor.m%对已经处理过的区分矩阵求核functioncore=cor(dism)m,n=size(dism);core1=zeros(1,n);number=0;fori=1:mnum=0;p=0;forj=1:nifdism(i,j)=0num=num+1;p=j;endend

9、ifnum=1core1(p)=1;number=number+1;endendifnumber=0core=0;elsecore=zeros(1,number);j=1;fori=1:numberwhilecore1(j)=0j=j+1;endcore(i)=core1(j);j=j+1;endend%uni.m%对区分矩阵的第i行和red(j,:)运算，即将a中%所有的1分别插入到red(j,:)中，待去掉包含关系functiontempred=uni(disa,red)m,n=size(red);num=0;fori=1:nifdisa(i)=0num=num+1;endendtempr

10、ed=ones(m*num,n);temp=;j=1;fori=1:numwhiledisa(j)=0j=j+1;endtemp=red;temp(:,j)=ones(m,1);tempred(i-1)*m+1:i*m,:)=temp;j=j+1;end%isxbelongtopos.m%判断x是否在正域pos中%x为索引值%返回值p,如果x在pos中p=1否则p=0functionp=isxbelongtopos(x,pos)m,n=size(pos);p=0;ifx<=0p=-1;return;endfori=1:mifx=pos(i)p=1;break;endend%isxybel

11、ongtoindD.m%判断x,y是否在indD中%x,y为索引值%返回值p,如果x,y在indD中p=1否则p=0functionp=isxybelongtoindD(x,y,d)ifx<=0|x>size(d)|y<=0|y>size(d)p=-1;return;endifd(x)=d(y)p=1;elsep=0;end约简后的决策表序号+千咳呼吸困海血液检测,高烧时射好桀聚多+塞战*:肌肉酸瘠乏力*胸膜漏头痛1、0.0,1,.0,0,Ox0.Ou0Oi2,0,111,0.1,0,0,t口，010.口，3,0.J0.,0、1.,o.TL,0.J0,0.,0、4,0,

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