Path: news.mathworks.com!not-for-mail
From: "zedong 
" <zdongwu@gmail.com>
Newsgroups: comp.soft-sys.matlab
Subject: a problem about symbolic polynomial.
Date: Mon, 29 Dec 2008 13:42:02 +0000 (UTC)
Organization: The MathWorks, Inc.
Lines: 52
Message-ID: <gjak3a$gh6$1@fred.mathworks.com>
Reply-To: "zedong 
" <zdongwu@gmail.com>
NNTP-Posting-Host: webapp-02-blr.mathworks.com
Content-Type: text/plain; charset="ISO-8859-1"
Content-Transfer-Encoding: 8bit
X-Trace: fred.mathworks.com 1230558122 16934 172.30.248.37 (29 Dec 2008 13:42:02 GMT)
X-Complaints-To: news@mathworks.com
NNTP-Posting-Date: Mon, 29 Dec 2008 13:42:02 +0000 (UTC)
X-Newsreader: MATLAB Central Newsreader 1639198
Xref: news.mathworks.com comp.soft-sys.matlab:509063


I have a polygon:
for example:
syms x y x0 x1 x2 y0 y1 y2
f=-1.0/12.0*x*(3*x*x*x*y2*y2*y0-3*x*x*x*y0*y0*y2-3
*x*x*x*y0*y1*y1+12*y*y*y*x0*x1*x1+12*y*y*y*x0*x0*x
2-12*y*y*y*x0*x0*x1+12*y*y*y*x2*x2*x1-12*y*y*y*x2*
x1*x1-12*y*y*y*x2*x2*x0-3*x*x*x*y2*y2*y1+3*x*x*x*y
2*y1*y1+3*x*x*x*y0*y0*y1+12*x2*x2*y0*x0*y1*y1+12*x
2*y0*y0*x1*x1*y2-12*x2*x2*y0*y0*x1*y1+12*x2*x2*y0*
y0*x1*y-12*x2*y0*y0*x1*x1*y-24*x2*x2*y0*y*y*x1+24*
x2*y0*y*y*x1*x1+12*x2*x2*y0*y*y*x0+12*y2*y2*x0*x0*
y1*x1-12*y2*x0*x0*y1*y1*x2-12*y2*y2*x0*y0*x1*x1+12
*y2*y2*x0*y*x1*x1-24*y2*x0*y*y*x1*x1-12*y2*y2*x0*x
0*y*x1-12*y2*x0*x0*y*y*x2+24*y2*x0*x0*y*y*x1+12*y*
x0*x0*y1*y1*x2-24*x2*x2*y0*x0*y1*y-24*x2*y0*y*x1*x
1*y2+24*x2*x2*y0*y*x1*y1+24*y2*x0*x0*y1*y*x2-24*y2
*x0*x0*y1*y*x1+24*y2*x0*y0*x1*x1*y-24*y*y*x0*x0*y1
*x2+12*y*y*x0*x0*y1*x1-12*y*y*x0*y0*x1*x1-12*y*x2*
x2*x0*y1*y1+24*y*y*x2*x2*x0*y1+12*y*y*x2*x1*x1*y2-
12*y*y*x2*x2*x1*y1+8*x*x*y2*y2*x0*y1+4*x*x*x2*y0*y
0*y2-8*x*x*x2*y0*y0*y1+8*x*x*y0*y0*x1*y2-4*x*x*y0*
y0*x1*y1+8*x*x*x2*y0*y1*y1-8*x*x*y2*x0*y1*y1-4*x*x
*y2*y2*x0*y0+4*x*x*y*x0*y1*y1-4*x*x*y*x2*y1*y1+4*x
*x*y0*x0*y1*y1-8*x*x*y2*y2*y0*x1+4*x*x*y2*y2*y*x1-
4*x*x*y2*y2*y*x0+4*x*x*y0*y0*y*x2-4*x*x*y0*y0*y*x1
+4*x*x*y2*y2*y1*x1-4*x*x*y2*y1*y1*x2-6*x*y2*y2*x0*
x0*y1-6*x*x2*x2*y0*y1*y1-6*x*y*y*x0*x0*y2+6*x*y*x2
*x2*y1*y1+6*x*y*y*x0*x0*y1-6*x*x2*x2*y0*y0*y+6*x*x
2*x2*y0*y0*y1+6*x*y2*x0*x0*y1*y1+6*x*y2*y2*x0*x0*y
-6*x*y*x0*x0*y1*y1-6*x*y*y*x2*x2*y1+6*x*y*y*x2*x2*
y0-6*x*y0*y0*x1*x1*y2+6*x*y0*y0*x1*x1*y-6*x*y0*y*y
*x1*x1+6*x*y2*y2*y0*x1*x1-6*x*y2*y2*y*x1*x1+6*x*y2
*y*y*x1*x1-8*x*x*y2*y*x1*y1-12*x*x2*y0*x0*y1*y1+12
*x*y2*y2*x0*y0*x1-12*x*x2*y0*y0*x1*y2-8*x*x*y*x0*y
0*y1+8*x*x*y*x2*y1*y2-8*x*x*y*x2*y0*y2+8*x*x*y0*y*
x1*y1+8*x*x*y*x0*y0*y2+12*x*y*y*x2*x0*y2-12*x*y2*y
2*x0*y1*x1+12*x*y2*x0*y1*y1*x2-12*x*y*y*x0*y0*x2+1
2*x*x2*y0*y0*x1*y1-12*x*y*y*x0*x1*y1-12*x*y*y*x2*x
1*y2+12*x*y*y*x2*x1*y1+12*x*y*y*x0*y0*x1+24*x*x2*y
0*y*x1*y2-24*x*x2*y0*y*x1*y1+24*x*x2*y0*y*x0*y1+24
*x*y2*x0*y*x1*y1-24*x*y*x0*y0*x1*y2-24*x*y*x2*x0*y
1*y2)


It's very complex.
Can I make it in x y order.

   (for example:
       f=x*y*x0+x*y*x1+x*x*x2+x*x*y2;
     I want to return:
      f=(x0+x1)*xy+(x2+y2)*x^2
      )