how to create a symmetric matrix?

[tanghanpost]

hi,
i want to create a symmetric matrix,like this: the upper is (-1), the lower is 1, and the diagonal is 0, i only find the command: sym(n), if n=100,it's crazy to input the matrix by hand.
thanks!
Tanghan

[EViews Gareth]

I'm not quite sure I can visualise the sym you're trying to create.

0s on the diagonal, (-1) above the diagonal and 1 below the diagonal? Surely that means it isn't symmetric?

[tanghanpost]

sorry,i mixed a mistake about it. i mean i want to create two matrix, one is symmetric, row=col=100, the diagonal=0, others=1. the second matrix is a simple matrix, row=100,col=100,the diagonal=0, but upper the diagonal is 1, lower the diagonal is (-1),
i find that the command sym(100) can create a symmetric matrix, but all cells=0, i don't know how to change it, or is there an other command to create matrix describe above?
thanks!
Tanghan

[EViews Gareth]

Code: Select all

sym mat1 = abs(@identity(100)-1) matrix mat2 = mat1 matrix mat2 = mat1 for !i=1 to 100 for !j=!i+1 to 100 mat2(!i,!j) = -1 next next