/**
* Extractor for a vector of
- * <code>dim</code> components of a
+ * <code>spacedim</code> components of a
* vector-valued element. The value of
- * <code>dim</code> is defined by the
+ * <code>spacedim</code> is defined by the
* FEValues object the extractor is applied
* to.
*
* FEValuesExtractors and in the @ref
* vector_valued module.
*
+ * Note that in the current context, a
+ * vector is meant in the sense physics
+ * uses it: it has <code>spacedim</code>
+ * 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.
+ *
* @ingroup feaccess vector_valued
*/
struct Vector
/**
* A class representing a view to a set of
- * <code>dim</code> components forming a
+ * <code>spacedim</code> components forming a
* vector part of a vector-valued finite
* element. Views are discussed in the
* @ref vector_valued module.
*
+ * Note that in the current context, a
+ * vector is meant in the sense physics
+ * uses it: it has <code>spacedim</code>
+ * 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.
+ *
* @ingroup feaccess vector_valued
*/
template <int dim, int spacedim=dim>