6CYANA: gradient - CYANA command

Parameters: step=<real>                    (default: 0.000001)
            cutoff=<real>                  (default: -1.0)

This function computes the gradient, i.e. the partial derivatives
of the target function against the torsion angle, numerically and
compares the result with the gradient computed by the (normal)
analytic method. The numerical derivatives are calculated with the
step size given by the 'step' parameter, as well as by using a 10
times smaller and a 10 times larger step size. The deviation of the
analytical gradient from the three numerically calculated gradient
values are reported for all torsion angles for which the maximal
absolute deviation exceeds the value set by the 'cutoff' parameter.

This command is useful to check the analytical gradient calculation
for correctness after a change of the target function and gradient
calculation.
