[Please Help] How to get coefficient list from a Series Command
- To: mathgroup at smc.vnet.net
 - Subject: [mg114416] [Please Help] How to get coefficient list from a Series Command
 - From: Autt <kajornrungsilp.i at gmail.com>
 - Date: Fri, 3 Dec 2010 06:30:55 -0500 (EST)
 
Greeting,
I've a list issued from  multivariate series like : K={a1+a2*x +a3*y
+a4*x^2*+a5*x*y +a6*y^2 }
I need to have {a1, a2 , a3 ,a4,a5,a6}
 How to do that please?
e.g.
n = 3
u = Normal[Series[x^4 + y^4 + x^2, {x, 5, n}, {y, 5, n}]]
c[0] = {};
d = {};
q[0] = {};
For[k = 1 , k <= n - 1, k++,
 For[i = 0 , i <= k , i++,
  p[i, k - i] =
   SeriesCoefficient[u, {x, 5, i}, {y, 5, k - i}];
  q[k] = Union[{q[k - 1], {p[i, k - i]}}];
  d = Union[d, q[k]];
  Print[d];
Best regard,