function?[meanvec?P]?=?pca（fn?numcomps）
patchsize?=?41;
patchlen?=?patchsize*patchsize;

if?nargin????error（?‘Not?enough?input?arguments.‘?）;
end

disp（‘Reading?patch?file.‘）;

fid?=?fopen（fn?‘r‘）;
array?=?fscanf（fid?‘%d‘?[patchlen?inf]）;

disp（‘Computing?covariance?matrix‘）;
meanvec?=?mean（array?2）;
meanarray?=?repmat（meanvec?1?size（array2））;
A?=?array-meanarray;
covA?=?A*A‘;

disp（‘Computing?principle?components.‘）;
[V?D]?=?eig（covA）;

P?=?V（:?（size（V?2）?-?numcomps?+?1）?:?size（V?2））;
P?=?fliplr（P）;

figure（3）;
plot（flipud（diag（D）））;

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

?????文件??????31538??2007-08-29?23:45??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\aclocal.m4

?????文件?????????19??2004-01-27?06:24??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\AUTHORS

?????文件??????????0??2004-01-27?06:24??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\ChangeLog

?????文件????????557??2007-08-29?23:45??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\config.h.in

?????文件?????144899??2007-08-29?23:45??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\configure

?????文件????????573??2004-03-22?10:31??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\configure.ac

?????文件???????1887??2004-01-27?06:24??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\COPYING

?????文件??????12123??2004-01-27?06:24??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\depcomp

?????文件?????????90??2004-01-27?06:24??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\docs\README

?????文件???????7843??2004-01-27?06:24??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\Doxyfile

?????文件???????1473??2004-04-23?10:39??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\gathergrads.cc

?????文件????????921??2004-04-23?10:39??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\getpatches.cc

?????文件????1806948??2004-01-27?06:24??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\gpcavects.txt

?????文件??????10435??2007-08-29?23:43??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\image.cc

?????文件???????3224??2004-01-27?06:24??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\image.h

?????文件???????9236??2004-01-27?06:24??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\INSTALL

?????文件???????5569??2004-01-27?06:24??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\install-sh

?????文件??????18019??2004-06-06?11:49??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\keypoint.cc

?????文件???????6915??2004-04-23?10:42??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\keypoint.h

?????文件????????716??2007-08-29?23:44??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\Makefile.am

?????文件??????20571??2007-08-29?23:45??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\Makefile.in

?????文件??????10270??2004-01-27?06:24??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\missing

?????文件???????1801??2004-01-27?06:24??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\mkinstalldirs

?????文件??????????0??2004-01-27?06:24??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\NEWS

?????文件????????899??2004-01-27?09:30??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\README

?????文件????????795??2004-01-27?06:24??PCA-SIFT代碼\pca-sift\pcasift-0.91nd\recalckeys.cc

?????文件????????559??2004-04-23?10:36??PCA-SIFT代碼\pca-sift\training-matlab\training\pca.m

?????文件????????627??2004-04-23?10:36??PCA-SIFT代碼\pca-sift\training-matlab\training\pcag.m

?????文件????????365??2004-04-23?10:36??PCA-SIFT代碼\pca-sift\training-matlab\training\ploteigs.m

?????文件????????571??2004-04-23?10:36??PCA-SIFT代碼\pca-sift\training-matlab\training\ploteigs2.m

............此處省略13個文件信息