Civil Engineering Reference
In-Depth Information
2.2.1
ROW AND COLUMN MATRICES
A
row matrix
is a matrix that reduces to a single row (
n
= 1).
[]
=
[
]
Aaaa a
m
11
12
13
1
Similar to a row matrix, a
column matrix
is a matrix that reduces to a
single column (
m
= 1).
a
a
a
11
21
[]
=
A
31
a
n
1
2.2.2
SQUARE MATRIX
A matrix in which the number of rows is equal to the number of columns
(
n
=
m
) is referred to as a
square matrix
.
aaa
a
11
12
13
1
n
aaa
a
21
22
23
2
n
[]
=
A
aaa
a
31
32
33
3
n
a
nn
aaa
n
1
n
2
n
3
Square matrices are unique because they are the only matrix that has a
reciprocal or invert as described later in this section. Several types of
square matrices exist such as the diagonal matrix, the identity matrix, the
triangular matrix, and the invert matrix.
2.2.3
DIAGONAL MATRIX
A
diagonal matrix
is defined as a matrix where all elements outside of the
principal diagonal
are equal to zero. The diagonal running from the upper
left corner of the array to the lower right corner is considered the principal
diagonal.
