CYANA Command: gradient: Difference between revisions

From CYANA Wiki
Jump to navigation Jump to search
m (1 revision)
 
 
Line 7: Line 7:
== Description ==
== Description ==


This function computes the gradient, i.e. the partial derivatives
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 given ''step'' size given, as well as with 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 given ''cutoff'' value.
of the target function against the torsion angle, numerically and
This command is useful to check the analytical gradient calculation for correctness after a change to the implementation of the target function and/or gradient calculation.
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.

Latest revision as of 14:06, 7 August 2009

Parameters

step=real
(default: 0.000001)
cutoff=real
(default: -1.0)

Description

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 given step size given, as well as with 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 given cutoff value. This command is useful to check the analytical gradient calculation for correctness after a change to the implementation of the target function and/or gradient calculation.