check if a square matrix is diagonal
- To: mathgroup at smc.vnet.net
- Subject: [mg115286] check if a square matrix is diagonal
- From: benyaya <xiaochu at gmail.com>
- Date: Thu, 6 Jan 2011 02:06:17 -0500 (EST)
What I try to do is extract the diagonal, subtract if from the matrix,
then compare the new matrix with 0.
My code doesn't work out though, can anyone help? thanks a lot.
checkIfDiagonalMatrix[m_] = Module[{d, mtemp},
d = Dimensions[m];
mtemp = DiagonalMatrix[Diagonal[m]] - m;
If[mtemp == Table[Table[0, {i, 1, d}], {i, 1, d}],
True,
False]
]