資源簡介
粗糙集屬性約簡的MATLAB程序;用基于屬性重要度的粗糙集屬性約簡方法對決策表進行約簡,屬性重要度是根據信息熵定義的。

代碼片段和文件信息
%求條件熵(Conditional?Entropy)
function?H_CD=Condentropy(UIND_CIND_D)%H(Y/X)=-sum(p(Xi)sum(p(Yj/Xi)log(p(Yj/Xi))))
%--------輸入---------
%?IND_C?????IND(C)?????由條件屬性集合或其子集劃分的不可分辨關系????[{x1}{x2x3x4}........]????
%?IND_D?????IND(D)?????由決策屬性集合劃分的不可分辨關系???????????[{y1}{y2y3y4}........]
%?U?????????論域????????字符串數組???????????????????????????????[X1X2X3X4........]
%-----------輸出---------
%?H_CD??????條件熵??????????一個數值????????如:0.0063
%===============================================================
l=numel(IND_C);m=numel(IND_D);
for?i=1:l
????pC(i)=numel(IND_C{i})/(numel(U));%p(X1)=|X1|/|U|
end
for?i=1:l
????for?j=1:m
???????x=numel(intersect((IND_D{j})(IND_C{i})))/(numel(IND_C{i}));%p(Y/X)=|Y&&X|/|X|
???????if?x==0
???????????pCD0(ji)=0;
???????else?pCD0(ji)=-x*log2(x);
???????end
????end
????pCD(i)=sum(pCD0(:i));
end
H_CD=0;
for?i=1:l
????H_CD=H_CD+pC(i)*pCD(i);
end?
?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件?????????974??2019-06-24?20:55??Condentropy.m
?????文件?????????857??2019-07-17?17:20??Core_relative.m
?????文件???????16059??2019-07-27?10:57??easy.xlsx
?????文件?????????344??2019-07-17?16:47??IND.m
?????文件?????????755??2019-06-22?09:00??POS.m
?????文件?????????563??2019-09-23?20:40??readme.txt
?????文件?????????570??2019-08-01?06:40??SGF.m
?????文件????????1377??2019-09-23?20:34??tiaoshi2.m
?????文件????????1133??2019-07-29?07:49??value_reduct1.m
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