Re: creating a symbolic square symmetric matrix
- To: mathgroup at smc.vnet.net
- Subject: [mg66327] Re: creating a symbolic square symmetric matrix
- From: dh <dh at metrohm.ch>
- Date: Wed, 10 May 2006 06:33:06 -0400 (EDT)
- References: <e3pege$ifq$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi,
simply create the matrix the way you want it:
n = 4;
mat = Table[If[i > j, Subscript[a, j, i], Subscript[a, i, j]], {i, n},
{j, n}]
Daniel
ravi wrote:
> Hi,
> First, I created a square matrix with the following command :
> n=4;
> mat=Table[Subscript[a,i, j],{i,n},{j,n}]
> In the same style, I would like to create a symmetric matric where all
> a[i, j] is replaced by a[j,i] for i>j. For i<=j, the coefficients
> remain in place.
> I tried to use the replace command :
> Replace[mat,Subscript[a,i,j]->Subscript[a,j,i]]
> This just interchanged the elements. I want this replacement only for
> the lower or upper triangular matrix elements.
> Would appreciate tips of doing a conditional substitution.
> /ravi
>