Re: How to construct symmetric matrix from just a one half matrix

*To*: mathgroup at smc.vnet.net*Subject*: [mg110390] Re: How to construct symmetric matrix from just a one half matrix*From*: "Nasser M. Abbasi" <nma at 12000.org>*Date*: Wed, 16 Jun 2010 05:39:12 -0400 (EDT)*References*: <hv76li$k4j$1@smc.vnet.net>*Reply-to*: nma at 12000.org

On 6/14/2010 11:30 PM, dragec 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 > one way: a = {{1, 0, 0, 0}, {2, 3, 0, 0}, {4, 9, 5, 0}, {2, 2, 3, 4}}; Transpose[LowerTriangularize[a, -1]] + a {{1, 2, 4, 2}, {2, 3, 9, 2}, {4, 9, 5, 3}, {2, 2, 3, 4} } --Nasser