%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%author:?bin_chen
%%date:?2017-10-6
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%?download?data
clear;
%?mnist
images?=?loadMNISTImages（‘train-images.idx3-ubyte‘）;
labels?=?loadMNISTLabels（‘train-labels.idx1-ubyte‘）;

%?cifar10
%?cifar_train_data1=load（‘cifar-10-matlab/data_batch_1‘）;
%?cifar_train_data2=load（‘cifar-10-matlab/data_batch_2‘）;
%?cifar_train_data3=load（‘cifar-10-matlab/data_batch_3‘）;
%?cifar_train_data4=load（‘cifar-10-matlab/data_batch_4‘）;
%?cifar_train_data5=load（‘cifar-10-matlab/data_batch_5‘）;
%?
%?images1=double（cifar_train_data1.data）;
%?images2=double（cifar_train_data2.data）;
%?images3=double（cifar_train_data3.data）;
%?images4=double（cifar_train_data4.data）;
%?images5=double（cifar_train_data5.data）;
%?images=[images1;images2;images3;images4;images5]‘;
%?labels1=（cifar_train_data1.labels）;
%?labels2=（cifar_train_data2.labels）;
%?labels3=（cifar_train_data3.labels）;
%?labels4=（cifar_train_data4.labels）;
%?labels5=（cifar_train_data5.labels）;
%?labels=double（[labels1;labels2;labels3;labels4;labels5]）;

%???image_mean=mean（images）;
%???images=images-repmat（image_meansize（images1）1）;

%?images?=?V_pca‘?*?images;??????????????%降維后的訓練數據??
%%?normalize（正則化）
L2?=?sum（images.^2）.^0.5;???????????%每個樣本特征值的二范距離
L2n?=?repmat（L2size（images1）1）;?
images=images./L2n;
clear?L2;
clear?L2n;
%%?PCA?dimensionality?reduction
C?=?double（images?*?images‘）;
[V?D]?=?eig（C）;??????????????????????%?V:特征向量??D：特征值構成的對角矩陣
D=diag（D）;
%?D?=?（fliplr（diag（D）‘））‘;????????????
D?=?cumsum（D）?/?sum（D）;?????????????????%最后一個元素為1
k?=?find（D?>=?1e-2?1）;???????????????%?忽略1%的能量
V_pca?=?V（:?k:end）;????????????????????%?保留部分特征
clear?C;
clear?D;
clear?V;
images?=?V_pca‘?*?images;?????
%%?training?part
img_i={};?????????????????????????????????????????
priori_i=zeros（101）;?????????????????????????????%?先驗概率
u_i=zeros（size（images1）10）;?????????????????????%?平均值
sigma_i=zeros（size（images1）size（images1）10）;??%?每一類的協方差矩陣
sigma=zeros（size（images1））;??????????????????????%?整體協方差矩陣
for?i=0:9
??[loc~]=find（labels==i）;
??img_i{i+1}=images（:loc）;
??priori_i（i+1）=size（img_i{i+1}2）/size（images2）;??????????????%先驗概率
??u_i（:i+1）=mean（img_i{i+1}2）;????????????????????????????????%第i類特征的均值
??x_u=img_i{i+1}-repmat（u_i（:i+1）[1size（img_i{i+1}2）]）;?????%特征值-平均值
??%?每一類的協方差矩陣
??sigma_i（::i+1）=x_u*x_u‘/size（img_i{i+1}2）+0.001*eye（size（images1））;????%加擾動，防止奇異
??%?整體協方差矩陣
??sigma=sigma+x_u*x_u‘;
end
sigma=sigma/size（images2）+0.001*eye（size（images1））;

%%?test?part
test_images?=?loadMNISTImages（‘t10k-images.idx3-ubyte‘）;
test_labels?=?loadMNISTLabels（‘t10k-labels.idx1-ubyte‘）;

%?cifar_test_data=load（[‘cifar-10-matlab\‘?‘test_batch.mat‘]）;
%?test_images=double（cifar_test_data.data）;
%?test_images=test_images‘;
%?test_labels=double（cifar_test_data.labels）;

test_images?=?V_pca‘?*?test_images;???%?與訓練數據按照同樣的方式進行降維
%?normalize
l2=sum（test_images

?屬性????????????大小?????日期????時間???名稱
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?????文件???????4434??2017-10-10?13:38??bayes分類器\bayes_10_cla.m

?????文件???????3516??2017-10-10?13:37??bayes分類器\bayes_2_cla.m

?????文件????????811??2011-04-27?23:02??bayes分類器\loadMNISTImages.m

?????文件????????516??2011-04-25?17:32??bayes分類器\loadMNISTLabels.m

?????文件????7840016??1998-01-26?23:07??bayes分類器\t10k-images.idx3-ubyte

?????文件??????10008??1998-01-26?23:07??bayes分類器\t10k-labels.idx1-ubyte

?????文件???47040016??1996-11-18?23:36??bayes分類器\train-images.idx3-ubyte

?????文件??????60008??1996-11-18?23:36??bayes分類器\train-labels.idx1-ubyte

?????目錄??????????0??2017-12-04?01:18??bayes分類器

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?????????????54959325????????????????????9