Skip to main content


The easifemClasses (henceforth, the Classes) library, forms the second level of EASIFEM library. This library contains many useful high-level objects, which are important for implementing FEM. The main programming paradigm of Classes library is object-oriented programming.

Use association​

USE easifemClasses

Key features​


  • TODO add key-features to easifemClasses

Similar to the Base library, the Classes library has two directories in the src directory:

  1. modules
  2. submodules

The modules directory mainly contains following items:

  1. Type definition including methods
  2. Header and interface of methods

The πŸ“submodules directory contains the implementation of the methods that are defined in the modules directory.

  • In addition, each class has its own subdirectory in the modules and submodules directory.
  • For example, the directory of Domain_ class is Domain, the directory of Mesh_ class is Mesh.
  • In this way, modules/Domain will define the Domain_ class and interface of methods, whereas submodules/Domain will include the submodules that implementes the methods defined inside modules.
  • The name of the module which defines Domain_ class is Domain_Classs, and it is included in the file called Domain_Class.F90.
  • The submodule, which defines methods (for example, constructor methods) will be included in Domain_Class@ConstructorMethods.F90, Domain_Class@IOMethods, etc.

If you want to implement a class called XXX_, then perform following task:

  1. Make a subdirectory XXX in src/modules and src/submodules
  2. In both XXX make a subdirectory XXX/src
  3. Create a file modules/XXX/src/XXX_Class.F90 and define a module called XXX_Class:
  4. Create submodules in submodule/XXX/src/XXX_Class@CategoryofMethods.F90 and implement the methods.
!! Use modules
!! Define class here


easifemClasses currently contains following modules:

Gmsh_ClassInterface to Gmsh libraryMesh
CommandLine_MethodFortran library for making comand line applications.CLI
ExceptionHandling_ClassFortran library for error handlingUtility
FPL_MethodFortran parameter listFEM
FilesCollection of modules related to File IO.IO
ElementFactoryFinite element factoryFEM
IntList_ClassLinked list of integersContainer
RealList_ClassLinked list of realsContainer
StringList_ClassLinked list of stringsContainer
ElementList_ClassLinked list of finite elementsFEM
ElementPointerVector_ClassDynamic vector of element pointersFEM
Mesh_ClassFinite element mesh classFEM
MeshPointerVector_ClassDynamic vector of mesh pointersFEM
Domain_ClassDomain classFEM
DomainUtilityA module for additional methods on Domain.FEM
DomainConnectivity_ClassDomain connectivity classFEM
MeshSelection_ClassA class for selecting the region of domain.FEM
MSHFile_ClassClass for Gmsh`s msh fileFEM
AbstractVector_ClassAbstract class for vectors.FEM
Vector_ClassConcrete class for vectors.FEM
FieldCollection of modules which defines classes for finite element fields.FEM
FieldFactoryFactory for fieldsFEM
AbstractLinSolver_ClassAbstract class for linear solverFEM
LinSolver_ClassNative linear solver class.FEM
LinSolver_FactoryFactory for linear solvers.FEM
AbstractBC_ClassAbstract class for boundary conditionsFEM
DirichletBC_ClassClass for Dirichlet boundary conditions.FEM
NeumannBC_ClassClass for Neumann boundary conditions.FEM
NitscheBC_ClassClass for Nitsche boundary conditions.FEM
PolynomialFactoryFactory of polynomialsFEM
UserFunction_ClassUser function classFEM
RefElementFactoryFactory of reference elementsFEM
FiniteElementFactoryFactory of finite elements.FEM
Tree3R_ClassTree data structure for 3 term recurrence relation.Math
Plot_MethodCollection of methods for plotting.FEM