Re: Matrix operation

*To*: mathgroup at smc.vnet.net*Subject*: [mg125774] Re: Matrix operation*From*: Dana DeLouis <dana2010 at me.com>*Date*: Mon, 2 Apr 2012 04:22:07 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

> - s2[i, j] = s1[i, j] + 4 * s1[i - 1, j] where i == 4 Hi. Just another option similar to others: (Not sure if you meant a negative sign in front, but easy to adjust) s2 = s1; r = 4; s2[[r]] = s2[[r]] + 4*s2[[r - 1]]; = = = = = = = = = = HTH :>) Dana DeLouis Mac & Math 8 = = = = = = = = = = On Mar 31, 4:46 am, Andrey Demidov <andrey.demi... at gmail.com> wrote: > Hi, > > I have a matrix: > > >> s1 = {{0, 4, 3, 6, 1, 0, 0, 30}, {0, 6, 16, 8, 0, 1, 0, 256}, {0, 4, 1, > > 10, 0, 0, 1, 9}, {1, -2, -4, -3, 0, 0, 0, 0}} > > >> MatrixForm[s1] > > Now, I need to get another matrix (s2) where: > > - s2[i, j] = s1[i, j] where i <> 4 > - s2[i, j] = s1[i, j] + 4 * s1[i - 1, j] where i == 4 > > What is the best way to get s2 ?