function?fx=Dx_backward（f）;
%?Dx_backward（f）?computes?backward?difference?with?respect?to?x?（or?j?the
%?idex?of?column）?for?coordinate?system?as?below
%?
%
%???????????x（j）
%????????|---------->
%????y（i）|
%????????|
%????????|
%????????V
%
%?Copyright?（c）?2001--2006?by?Chunming?Li
%?Author:?Chunming?Li?11/02/2003
%?Revision?by?Chunming?Li?7/24/2005

[nrnc]=size（f）;
fx=zeros（nrnc）;
fx（:2:nc）=f（:2:nc）-f（:1:nc-1）;

fx（:1）=f（:2）-f（:1）;?%?for?the?first?column?use?the?forward?difference?as?the?backward?difference

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

?????文件??????90651??2006-05-18?12:30??幾何活動輪廓\1997__GAC__Vicent?Caselles_LiChunMing\112.txt

?????文件?????120054??2006-04-22?13:07??幾何活動輪廓\1997__GAC__Vicent?Caselles_LiChunMing\3.bmp

?????文件????????543??2006-01-15?14:02??幾何活動輪廓\1997__GAC__Vicent?Caselles_LiChunMing\Dx_backward.m

?????文件????????555??2006-01-15?14:01??幾何活動輪廓\1997__GAC__Vicent?Caselles_LiChunMing\Dx_forward.m

?????文件????????538??2006-01-15?14:03??幾何活動輪廓\1997__GAC__Vicent?Caselles_LiChunMing\Dy_backward.m

?????文件????????545??2006-01-15?13:58??幾何活動輪廓\1997__GAC__Vicent?Caselles_LiChunMing\Dy_forward.m

?????文件???????1267??2011-01-12?16:29??幾何活動輪廓\1997__GAC__Vicent?Caselles_LiChunMing\EVOLUTION_GAC.m

?????文件???????1621??2006-10-18?21:53??幾何活動輪廓\1997__GAC__Vicent?Caselles_LiChunMing\GAC_demo.asv

?????文件???????1676??2011-02-25?11:02??幾何活動輪廓\1997__GAC__Vicent?Caselles_LiChunMing\GAC_demo.m

?????文件????????456??2006-03-22?22:40??幾何活動輪廓\1997__GAC__Vicent?Caselles_LiChunMing\gradientNorm_upwind.m

?????文件???????8134??2004-07-05?18:59??幾何活動輪廓\1997__GAC__Vicent?Caselles_LiChunMing\noisyImg.bmp

?????文件???????3929??2006-03-23?00:29??幾何活動輪廓\1997__GAC__Vicent?Caselles_LiChunMing\reinit_SD.m

?????文件????????120??2006-03-22?23:05??幾何活動輪廓\1997__GAC__Vicent?Caselles_LiChunMing\sdf2circle.m

????..A.SH.??????7680??2006-03-16?19:51??幾何活動輪廓\1997__GAC__Vicent?Caselles_LiChunMing\Thumbs.db

?????文件????????578??2006-05-19?11:34??幾何活動輪廓\1997__GAC__Vicent?Caselles_LiChunMing\Untitled.asv

?????文件????????622??2006-05-19?11:42??幾何活動輪廓\1997__GAC__Vicent?Caselles_LiChunMing\Untitled.m

?????文件??????14286??2005-07-25?15:45??幾何活動輪廓\1997__GAC__Vicent?Caselles_LiChunMing\vessel.bmp

?????文件??????28224??2006-05-17?22:24??幾何活動輪廓\1997__GAC__Vicent?Caselles_LiChunMing\wx.txt

????..A.SH.?????????9??2006-09-27?08:09??幾何活動輪廓\1997__GAC__Vicent?Caselles_LiChunMing\_desktop.ini

?????文件???????1176??2006-05-17?17:30??幾何活動輪廓\1997__GAC__版本2\GACmodel\calcspeed.m

?????文件????????666??2006-04-27?08:31??幾何活動輪廓\1997__GAC__版本2\GACmodel\createimage.m

?????文件????????880??2006-04-27?08:27??幾何活動輪廓\1997__GAC__版本2\GACmodel\init_u.m

?????文件????????825??2006-05-17?17:23??幾何活動輪廓\1997__GAC__版本2\GACmodel\isfront.m

?????文件???????1425??2011-01-12?16:18??幾何活動輪廓\1997__GAC__版本2\GACmodel\levelset.m

?????文件????????969??2011-01-17?16:17??幾何活動輪廓\1997__GAC__版本2\GACmodel\main.m

?????文件????????261??2006-04-22?12:58??幾何活動輪廓\1997__GAC__版本2\GACmodel\readimage.m

?????文件????????499??2006-04-27?08:20??幾何活動輪廓\1997__GAC__版本2\GACmodel\re_init_u.m

?????文件????????767??2006-04-27?08:16??幾何活動輪廓\1997__GAC__版本2\GACmodel\stopfunction.m

????..A.SH.????708096??2006-05-17?17:38??幾何活動輪廓\1997__GAC__版本2\GACmodel\Thumbs.db

?????文件?????307712??2011-01-11?13:14??幾何活動輪廓\1997__GAC__版本2\GAC的水平集方法.doc

............此處省略76個文件信息