JCMsuite allows to efficiently compute derivatives of simulation results with respect to parameters influencing geometrical shapes, material or source properties. This yields a linear approximation of the output results with respect to parameters. The section DerivativeParameter allows to define parameter dependencies by referencing their corresponding TreeEntry, the Path within the .jcm input tree to the named, scalar parameter r, and to define an optional Scaling.

The following code snippet is taken from the tutorial example Shape Derivatives, where the DerivativeParameter is used to parameterize the shape of a cylinder defined in the layout.

DerivativeParameter {
  Name = "Height"
  TreeEntry = Layout3D/Extrusion/MultiLayer/CylinderLayer/Thickness
  TreeEntry {
    Path = Layout3D/Extrusion/MultiLayer/TopLayer/Thickness
    Scaling = -1.0

Multiple TreeEntry definitions can be used if a parameter influences more the one value in the .jcm input tree.


Only the last of multiple TreeEntry definitions pointing to the same scalar value is considered.