[T.D.]

Hi FOAMers,

We know that in OpenFOAM the matrix coefficients are split into diag, lower and upper ones with an attention for boundary cells in the .diag() coefficients.
For example:
Taking any problem after discretizaton it becomes: KU=F , and we need to find i.e. the U field. OpenFoam classes split the matrices into: (A+H')U=F <=> AU = (F-H'U) for special treatments like sparse matrices.

We know that we can access diag(),lower(), upper(), source(), .A(), .H1(), .H(), and .psi() in OpenFOAM.

My Question is:

How can we re-Assemble-Back correctly the problem to get the two whole matrices: K and F from all what is available in the OpenFOAM classes like diag(),lower(), upper(), source(), .A(), .H1(), .H(), and .psi(), etc.. ?
Any ideas ?

Thanks

Best regards,

T.D.