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%%%%%%%%%%%%%%?????支持向量機的核心程序，計算判決方程的權系數等參量?????????%%%%%%%%%%%
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function?[alpha_star?a_star?bias?p?b]=ddsvmm（xysigmacy）
xx=x;
yy=y;
ker_param=sigma;???????????????????????????????????????%%%%%%%%設置核函數參數
[Dim?Nf]=?size（xx）;
z?=?2*（yy==cy）?-?1;??????????????????????????????????????%%%%%%%將類別矩陣轉化為邏輯矩陣，構造二類分類器
p?=?zeros（Nf）;
for?i?=?1:Nf
?????p（:i）=?exp（-sum（（xx-xx（:i）*ones（1Nf））.^2）‘/（2*ker_param^2））;???????%%選用徑向基函數作為核函數
end
????alpha_star?=?quadprog（（z‘*z）.*（p‘*p）?-ones（1?Nf）?[]?[]?z0?0）;??%%計算權值
????a_star?=?p*（alpha_star.*z‘）;
????in?=?find（alpha_star?>?0）;?????????????????????????????????????????????%%找權值為正的下標?
if?isempty（in）
??????bias?=?0;???????????????????????????????????
??else
???B=?z（in）?-?a_star‘*?p（:in）;?????????????????????????????????????????????%%%求偏置
??????bias?=?mean（B）;
end
??sv?=?find（abs（a_star）?>?1e-10）;???????????????????????????????????????????%%找支持向量
Nsv?=?length（sv）;
if?isempty（sv）
??error（‘No?support?vectors?found‘）;
else
??disp（[‘Found?‘?num2str（Nsv）?‘?support?vectors‘]）
end
b?=?1/sqrt（sum（a_star.^2））;????????????????????????????????????????????????%%?求最大化邊緣

?屬性????????????大小?????日期????時間???名稱
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?????文件???????1411??2011-06-21?11:09??ds仿真\ddsvmm.m

?????文件????????870??2011-07-10?10:52??ds仿真\ds.m

?????文件???????1150??2008-06-20?10:48??ds仿真\lmsdemo.m

?????目錄??????????0??2012-01-09?20:38??ds仿真

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?????????????????3431????????????????????4