function?[select_feature]=fs_SD_Gread（sDatan）
%%?fs_SD_Gread?函數返回基于標準差的貪心算法得到的屬性約簡
%%?sData：?數據
%%?n:?控制領域大小的參數

[rowcolumn]=size（sData.data）;

aaaaa=0;
%%?得到鄰域關系
neighborRelation=my_SD_getNeighborRelation（sDatan）;
r=neighborRelation{column+1};

n=[];
x=0;
base=ones（row）;
pos=[];
attrinu=column;
for?j=attrinu:-1:1
????sig=[];????
????
????%縮減決策屬性的鄰域關系和base矩陣
????r（pos:）=[];
????r（:pos）=[];
????base（:pos）=[];
????base（pos:）=[];
????
????%當所有元素都剔除時，跳出
????if?isempty（base）
????????break;
????end
????
????%縮減鄰域關系
????for?l=1:attrinu
????????a=neighborRelation{l};
????????a（pos:）=[];
????????a（:pos）=[];
????????neighborRelation{l}=a;
????end
????%poss?用來存放正域即下近似
????poss=cell（1attrinu）;
????
????for?l=1:attrinu
????????r2=neighborRelation{l};
????????r1=min（r2base）;????
????????
?????????????
????????rrr=size（r12）;
????????importance=row-rrr;
????????
????????po=zeros（rrr）;
????????aaaaa=aaaaa+rrr;
????????for?i=1:rrr???????????
????????????temp=min（[r1（i:）;r（i:）]）;
????????????incluse=sum（temp）/sum（r1（i:））;
????????????if?incluse>=1
????????????????po（i）=i;
????????????????importance=importance+sum（temp）/length（find（temp~=0））;
????????????end????????????
????????end
????????%?剔除po中的非零元素
????????po=po（po~=0）;%速度較快，比?a（~any（a1））=[]快
????????
????????poss{l}=po;
????????sig（l）=importance/row;
????end
?????
????[x1n1]=max（sig）;
????
????pos=poss{n1};
????x=[x;x1];
????len=length（x）;
????if?abs（x（len）-x（len-1））>0.001
????????base1=neighborRelation{n1};
????????base=min（basebase1）;????????
????????n=[n;n1];
????else
????????break
????end
end

select_feature=n;

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件???????1770??2010-08-16?18:50??FS_NRS_GREAD\fs_SD_Gread.m

?????文件????????881??2010-07-20?15:21??FS_NRS_GREAD\my_SD_getNeighborRelation.m

?????文件??????21567??2010-08-16?17:13??FS_NRS_GREAD\wine.mat

?????目錄??????????0??2010-08-20?22:33??FS_NRS_GREAD

-----------?---------??----------?-----??----

????????????????24218????????????????????4