A reconstructed D⁄ matrix, created from the product of the
calculated CST matrices, was then compared with the original D
matrix, and the iterative optimisation continued until the convergence
criterion is achieved or until a preselected number of cycles
is reached. The convergence criterion was achieved when the
variation of results between consecutive iterations fell below a
preset threshold value or when a certain number of iterations were
exceeded. In this work the convergence criterion used was 0.1%
and 50 iterations as maximum. The constrained iterative optimisation
is carried out until convergence is achieved or until a preselected
number of cycles are reached. The standard is 10 cycles