Re: Simultaneous difference equation

*To*: mathgroup at smc.vnet.net*Subject*: [mg30612] Re: Simultaneous difference equation*From*: "Allan Hayes" <hay at haystack.demon.co.uk>*Date*: Fri, 31 Aug 2001 04:09:37 -0400 (EDT)*References*: <9mkt9m$1vn$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Shusaku, <<DiscreteMath`RSolve` RSolve[{a11*x[t]+a12*y[t]==a13*x[t-1]+a14*y[t-1]+k1, a21* x[t]+a22*y[t]==a23*x[t-1]+a24*y[t-1]+k2}, {x[t],y[t]},t] Gives an answer - after a long wait. -- Allan --------------------- Allan Hayes Mathematica Training and Consulting Leicester UK www.haystack.demon.co.uk hay at haystack.demon.co.uk Voice: +44 (0)116 271 4198 Fax: +44 (0)870 164 0565 "Shusaku Yamamoto" <shusaku.yamamoto at buseco.monash.edu.au> wrote in message news:9mkt9m$1vn$1 at smc.vnet.net... > Hello, I have just started using (or more appropriately trying to use) > Mathematica. As you expect, I have a problem. I would like to know > Mathematica code for solving simultaneous difference eqation; for > example: > > a_11*x(t)+a_12*y(t)=a_13*x(t-1)+a_14*y(t-1)+k_1 > a_21* x(t)+a_22*y(t)=a_23*x(t-1)+a_24*y(t-1)+k_2 > > Or, in matrix notation, > > A_1*Y(t)=A_2*Y(t-1)+K > > t denotes time t, and t-1 is one period before time t. > > I have go through help menu in Mathematica. Yet, I could not get reached > to the topic of difference equation. If you know the code (or what to be > typed), could you reply this message? > > Thank you very much in advance. >