Re: How to construct symmetric matrix from just a one
- To: mathgroup at smc.vnet.net
- Subject: [mg110419] Re: How to construct symmetric matrix from just a one
- From: Bob Hanlon <hanlonr at cox.net>
- Date: Thu, 17 Jun 2010 02:04:21 -0400 (EDT)
SetAttributes[f, HoldAll];
f[mat_?MatrixQ] :=
Module[
{n = Length[mat]},
Table[
mat[[r, c]] = mat[[c, r]],
{r, n - 1}, {c, r + 1, n}];
m]
m = {{1, 0, 0, 0},
{2, 3, 0, 0},
{4, 9, 5, 0},
{2, 2, 3, 4}};
f[m]
{{1, 2, 4, 2}, {2, 3, 9, 2}, {4, 9, 5, 3}, {2, 2, 3, 4}}
Bob Hanlon
---- dragec <culinovic at gmail.com> wrote:
=============
please help me with simple to apply function that will construct
symmetric matrix from given just a half matrix with diagonal.
Eg:
From:
1 0 0 0
2 3 0 0
4 9 5 0
2 2 3 4
To give:
1 2 4 2
2 3 9 2
4 9 5 3
2 2 3 4