clear;
clc;
%讀取數(shù)據(jù)
trainImages?=?loadMNISTImages（‘train-images.idx3-ubyte‘）;??????
trainLabels?=?loadMNISTLabels（‘train-labels.idx1-ubyte‘）;
testImages?=?loadMNISTImages（‘t10k-images.idx3-ubyte‘）;
testLabels?=?loadMNISTLabels（‘t10k-labels.idx1-ubyte‘）;
%選取部分樣本進(jìn)行測(cè)試
testImages?=?testImages（:1:100）;
testLabels?=?testLabels（1:1001）;
%PCA降維
square?=?double（trainImages?*?trainImages‘）;
[eigVect?eigVal]?=?eig（square）;
eigVal?=?diag（eigVal）;??
eigVal?=?cumsum（eigVal）?/?sum（eigVal）;
k?=?find（eigVal?>=?5e-2?1）;
pca?=?eigVect（:?k:end）;
trainImages?=?pca‘?*?trainImages;
testImages?=?pca‘?*?testImages;?
%獲得樣本規(guī)模
[mn]?=?size（trainImages）;
[rs]?=?size（testImages）;

K?=?10;????????????????????????????????????????????????????????%K最好取20以下的數(shù)
testResults?=?zeros（1s）;
kLabels?=?zeros（1K）;
error?=0;
%開始訓(xùn)練
tic;
for?i?=?1?:?s
????%求出待測(cè)樣本與訓(xùn)練樣本的距離
????colImages?=?repmat（testImages（:i）1n）;?
????colImages?=?（trainImages?-?colImages）?.^?2;
????distance?=?sum（colImages）?.^?0.5;
????%找到離待測(cè)樣本最近的k個(gè)訓(xùn)練樣本
????[sortDistpos1]?=?sort（distance）;
????for?j?=?1?:?K
????????kLabels（j）?=?trainLabels（pos1（j））;
????end
????%訓(xùn)練樣本進(jìn)行投票得到待測(cè)樣本的類別
????count?=?tabulate（kLabels）;
????[maxCountpos2]?=?max（count（:2））;
????testResults（i）?=?count（pos2）;??
????fprintf（‘第%d張圖片\n‘i）;
end
%判斷訓(xùn)練結(jié)果
for?i?=?1?:?s
??if?（testResults（i）?~=?testLabels（i））
????error?=?error+1;
??end
end

fprintf（‘正確率為%d\n‘1-error/s）;
toc;

%?save?data?error;

?屬性????????????大小?????日期????時(shí)間???名稱
-----------?---------??----------?-----??----

?????文件???????1559??2017-11-14?19:36??matlab\KNN.m

?????文件????????837??2017-11-07?16:51??matlab\loadMNISTImages.m

?????文件????????535??2017-11-03?17:49??matlab\loadMNISTLabels.m

?????文件????????259??2017-11-13?17:13??matlab\Readme.txt

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

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

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

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

?????目錄??????????0??2017-11-13?17:02??matlab

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

?????????????54953238????????????????????9