Introduction

In the following we will demonstrate which steps the user has to pass to get from a general interface mask to a complete hierarchical interface. In each step we will first present the code from the interface mask (marked by horizontal lines) and afterwards discuss the neccessary modifications. The recipe and the example cover the 2D-case. The 3D-case is analogous.

The interface consists of the following routines:

• HMESH2D-routines
  • get_new_hmesh()
  • Routines to traverse the hierarchical mesh
    • interface_first_macro()
    • interface_next_macro()
    • interface_first_child()
    • interface_next_child()
    • interface_select_child()
    • interface_first_element()
    • interface_next_element()
  • Handling interface_elements
    • get_interface_element()
    • free_interface_element()
    • fill_interface_element_with_user_macro_element()
    • fill_interface_element_with_user_child_element()
  • Helement Description
    • element_world_to_coord()
    • element_coord_to_world()
    • helement_description_check_inside()
    • helement_description_neighbour()
    • helement_description_boundary()
    • helement_description_coord_of_parent()
  • Geometry error estimator
    • get_geometry_vertex_estimate()
    • get_geometry_element_estimate()
• Routines for functions on hierachical meshes
  • get_new_fhdata()
  • data_access_function()
  • local_information()
  • get_bounds()
  • Function error estimator
    • get_function_vertex_estimate()
    • get_function_element_estimate()

In order to illustrate the single steps we introduce a sample data structure. As the interface uses its own data structures we have to distinguish three kinds of data structures:

• the data structure of the user
• the internal GRAPE data structures
• the interface data structures

In the example the user data structures are called BISMESH, BELEMENTs and BELEMENT_MACRO. The task of the interface is to translate these structures into the respective internal GRAPE structures HMESH2D and HELEMENT2D. The interface employs so called INTERFACE_ELEMENTs to generate the HELEMENT2Ds.