In
linear algebra, a 'column vector' is an ''m'' × 1
matrix, i.e. a
matrix consisting of a single column of
elements.
:
The
transpose of a column vector is a
row vector and
vice versa.
The set of all column vectors forms a
vector space which is the
dual space to the set of all
row vectors.
Notation
To simplify writing column vectors in-line with other text, sometimes they are written as
row vectors with the
transpose operation applied to them.
:
For further simplification, writers also use the convention of writing both column vectors and
row vectors as rows but separating
row vector elements with
spaces and column vector elements with
commas. For example, if
is a
row vector, then
and
might be denoted as follows.
:
Operations
★
Matrix multiplication involves the action of multiplying each column vector of one
matrix by each
row vector of another
matrix.
★ The
dot product in a
Euclidean space involves both taking the
transpose of a column vector and multiplying the resulting
row vector with another column vector.