Eigen is a linear algebra library written in C++. It is shipped with the SOFA distribution in extlibs/
Which components in SOFA use Eigen ?
Eigen is used by ODE and DAE solvers in the Compliant plugin. The associated matrix classes, derived from BaseMatrix, are EigenSparseMatrix and EigenBaseSparseMatrix.
Moreover, some older specific components related to constraint resolution use Eigen. Note that it is not mandatory to use Eigen to have access to constraint resolution ! The following components become available when compiling with Eigen :