User`s guide
Reciprocal Condition
5-367
5Reciprocal Condition
Purpose Compute the reciprocal condition of a square matrix in the 1-norm.
Library Math Functions / Matrices and Linear Algebra / Matrix Operations
Description The Reciprocal Condition block computes the reciprocal of the condition
number for a square input matrix A.
y = rcond(A) % Equivalent MATLAB code
or
where κ is the condition number (κ ≥ 1), and y is the scalar sample-based output
(0 ≤ y < 1).
The matrix 1-norm, , is the maximum column-sum in the M-by-M
matrix A.
For a 3-by-3 matrix:
y
1
κ
---
1
A
1–
1
A
1
-------------------------------==
A
1
A
1
a
ij
i 1=
M
∑
1 jM≤≤
max=
a
11
a
12
a
13
a
21
a
22
a
23
a
31
a
32
a
33
a
13
a
23
a
33
++ A
3
=
a
12
a
22
a
32
++ A
2
=
a
11
a
21
a
31
++ A
1
=
A
1
A
1
A
2
A
3
,,()max=