Adjoint API

Overview

This page describes the API for adjoint-based sensitivities in Kratos.

Adjoint Variables

An adjoint variable is defined for each primal variable by prefixing the variable name with ADJOINT. For example, the adjoint variable of VELOCITY is ADJOINT_VELOCITY.

Adjoint Elements

Adjoint elements are created in the same way as regular elements. The function GetDofList returns the list of adjoint dofs.

CalculateFirstDerivativesLHS -> The adjoint matrix obtained from the gradient of the residual with respect to first derivatives of the primal variable.