Reference documentation for deal.II version Git 39b7d3efb0 2021-05-07 15:49:09 -0400
FEValuesExtractors::Vector Struct Reference

#include <deal.II/fe/fe_values_extractors.h>

## Public Member Functions

Vector ()

Vector (const unsigned int first_vector_component)

std::string get_name () const

## Public Attributes

unsigned int first_vector_component

## Detailed Description

Extractor for a vector of spacedim components of a vector- valued element. The value of spacedim is defined by the FEValues object the extractor is applied to. The result of applying an object of this type to an FEValues, FEFaceValues or FESubfaceValues object is of type FEValuesViews::Vector.

The concept of extractors is defined in the documentation of the namespace FEValuesExtractors and in the Handling vector valued problems module.

Note that in the current context, a vector is meant in the sense physics uses it: it has spacedim components that behave in specific ways under coordinate system transformations. Examples include velocity or displacement fields. This is opposed to how mathematics uses the word "vector" (and how we use this word in other contexts in the library, for example in the Vector class), where it really stands for a collection of numbers. An example of this latter use of the word could be the set of concentrations of chemical species in a flame; however, these are really just a collection of scalar variables, since they do not change if the coordinate system is rotated, unlike the components of a velocity vector, and consequently, this class should not be used for this context.

Definition at line 150 of file fe_values_extractors.h.

## ◆ Vector() [1/2]

 Vector< Number >::Vector ( )
inline

Default constructor. Initialize the object with an invalid component. This leads to an object that can not be used, but it allows objects of this kind to be put into arrays that require a default constructor upon resizing the array, and then later assigning a suitable object to each element of the array.

Definition at line 291 of file fe_values_extractors.h.

## ◆ Vector() [2/2]

 Vector< Number >::Vector ( const unsigned int first_vector_component )
inline

Constructor. Take the first component of the selected vector inside the FEValues object as argument.

Definition at line 296 of file fe_values_extractors.h.

## ◆ get_name()

 std::string Vector< Number >::get_name ( ) const

Return a string that uniquely identifies this finite element extractor.

Definition at line 32 of file fe_values_extractors.cc.

## ◆ first_vector_component

 unsigned int FEValuesExtractors::Vector::first_vector_component

The first component of the vector view.

Definition at line 155 of file fe_values_extractors.h.

The documentation for this struct was generated from the following files: