---
name: "reference_element"
section: "7rheolef"
platform: "linux"
package: "librheolef-dev"
version: "7.0-2+b1"
release: "Debian 10 (Buster)"
platforms: ["linux"]
url: "https://new.carta.tech/reference_element/7rheolef"
---

# reference\_element(7rheolef)

reference element

## NAME

**reference\_element** - reference element

## SYNOPSIS

The **reference\_element** class defines all supported types of geometrical elements in one, two and three dimensions. The set of supported elements are designate by a letter

- **p**

  point (dimension 0)

- **e**

  edge (dimension 1)

- **t**

  triangle(dimension 2)

- **q**

  quadrangle(dimension 2)

- **T**

  tetrahedron(dimension 3)

- **P**

  prism(dimension 3)

- **H**

  hexaedron(dimension 3)

## IMPLEMENTATION

```
class reference_element {
public:
// typedefs:
    typedef std::vector<int>::size_type size_type;
    // defines variant_type { p, t, q ..., H, ...};
    // in an automatically generated file :
    typedef size_type variant_type;
    static const variant_type
        p = 0,
        e = 1,
        t = 2,
        q = 3,
        T = 4,
        P = 5,
        H = 6,
        max_variant = 7;
// allocators/deallocators:
    reference_element (variant_type x = max_variant)
      : _x(x) { assert_macro (x >= 0 && x <= max_variant, "invalid type " << x); }
// initializers:
    void set_variant (variant_type x) { _x = x; }
    void set_variant (size_type n_vertex, size_type dim) { _x = variant (n_vertex, dim); }
    void set_name    (char name);
// accessors:
    variant_type variant() const { return _x; }
    char name() const { return _name[_x % max_variant]; }
    size_type dimension() const { return _dimension[_x]; }
    size_type size() const { return _n_vertex[_x]; }
    size_type n_subgeo(size_type subgeo_dim) const { return n_subgeo (variant(), subgeo_dim); }
    size_type n_edge() const { return n_subgeo(1); }
    size_type n_face() const { return n_subgeo(2); }
    size_type subgeo_size (size_type subgeo_dim, size_type loc_isid) const {
        return subgeo_n_node (_x, 1, subgeo_dim, loc_isid); }
    size_type subgeo_local_vertex(size_type subgeo_dim, size_type loc_isid, size_type loc_jsidvert) const {
        return subgeo_local_node (_x, 1, subgeo_dim, loc_isid, loc_jsidvert); }
    // TODO: use template<class T> instead of Float
    const point_basic<Float>& vertex (size_type iloc) const;
    friend Float measure (reference_element hat_K);
    Float side_measure (size_type loc_isid) const;
    void side_normal (size_type loc_isid, point_basic<Float>& hat_n) const;
// helpers:
    static variant_type variant  (char name);
    static variant_type variant  (size_type n_vertex, size_type dim);
    static char         name     (variant_type variant) { return _name     [variant]; }
    static size_type dimension   (variant_type variant) { return _dimension[variant]; }
    static size_type n_vertex    (variant_type variant) { return _n_vertex [variant]; }
    static size_type n_node      (variant_type variant, size_type order);
    static size_type n_sub_edge    (variant_type variant);
    static size_type n_sub_face    (variant_type variant);
    static size_type n_subgeo      (variant_type variant, size_type subgeo_dim);
    static size_type subgeo_n_node (variant_type variant, size_type order, size_type subgeo_dim, size_type loc_isid);
    static size_type subgeo_local_node (variant_type variant, size_type order, size_type subgeo_dim, size_type loc_isid, size_type loc_jsidnod);
    static variant_type first_variant_by_dimension (size_type dim) {
                return _first_variant_by_dimension[dim]; }
    static variant_type  last_variant_by_dimension (size_type dim) {
                return _first_variant_by_dimension[dim+1]; }
    static size_type first_inod_by_variant (variant_type variant, size_type order, variant_type subgeo_variant);
    static size_type  last_inod_by_variant (variant_type variant, size_type order, variant_type subgeo_variant)
       { return first_inod_by_variant (variant, order, subgeo_variant+1); }
    static size_type first_inod (variant_type variant, size_type order, size_type subgeo_dim)
       { return first_inod_by_variant (variant, order, first_variant_by_dimension(subgeo_dim)); }
    static size_type  last_inod (variant_type variant, size_type order, size_type subgeo_dim)
       { return first_inod_by_variant (variant, order,  last_variant_by_dimension(subgeo_dim)); }
    static void init_local_nnode_by_variant (size_type order, std::array<size_type,reference_element::max_variant>& loc_nnod_by_variant);
protected:
// constants:
    static const char      _name [max_variant];
    static const size_type _dimension [max_variant];
    static const size_type _n_vertex [max_variant];
    static const variant_type _first_variant_by_dimension[5];
// data:
    variant_type _x;
};

```

## COPYRIGHT

Copyright (C) 2000-2018 Pierre Saramito \<Pierre.Saramito@imag.fr\> GPLv3+: GNU GPL version 3 or later \<http://gnu.org/licenses/gpl.html\>. This is free software: you are free to change and redistribute it.  There is NO WARRANTY, to the extent permitted by law.