i have a linear system which i want to solve via dposv_(). But i have problem to understand how to give the matrix.

Until now i linearized all matrices in a simple array and put it as an argument. For example:

A = [1,2;3,4] -> A[1,2,3,4].

So for general formats i linearized row-wise. The routine dposv needs only:

On entry, the symmetric matrix A. If UPLO = 'U', the leading

* N-by-N upper triangular part of A contains the upper

* triangular part of the matrix A, and the strictly lower

* triangular part of A is not referenced.

How should i put the matrix in the array? Is lapack that intelligent that it internally extract the correct column values?

So for example if i have the matrix:

A= [1,0,0;

2,3,0;

-1,-2,-3]

would that be:

A[1,2,3,-1,-2,-3] with the character UPLO="L"

a correct input for dposv? How should i linearize a triangular matrix?

Thanks for any advice.

Greetings Mat