# etol

Specifies the tolerance for iterations of the partial differntial equation solvers: The syntax is:

    etol { tol }

where `tol` is the (floating point) numerical value for the error tolerance.

For finite difference solvers, this keyword is optional and is intended for mg-manual, mg-auto, and mg-para calculation types.

For finite element solvers, this keyword specifies the tolerance for error-based adaptive refinement during the solve-estimate-refine iterations of the finite element solver (fe-manual), where `tol` is the (floating point) numerical value for the error tolerance.