Overview:
-
A Hilbert matrix is an nxn matrix whose elements are given by eij = 1/i+j-1.
-
The elements of the Hilbert matrix are Unit fractions. For example, if n=3, the Hilbert matrix is
(1 1/2 1/3
1/2 1/3 1/4
1/3 1/4 1/5)
-
Unit fractions have one as their numerator. Unit fractions are of the form 1/n where n is an integer.
-
Hilbert matrices have several interesting properties
-
They are square matrices and symmetrical.
-
Their inverses contain all integer elements
-
The anti-diagonal of any Hilbert matrix are constants. i.e, The elements of the anti-diagonal will have the same values.
-
Hilbert matrices are ill-conditioned matrices whose condition numbers are very large. A large condition number means a small change in the input to the system of linear equations as represented by a matrix will result in larger changes in the output.
-
-
Hilbert matrices are used in image processing to obtain gray scale images. They are used in cryptography and security applications.
Example:
# Example Python program that creates a Hilbert matrix import scipy.linalg as sclg # A Hilbert matrix of size 6x6 |
Output:
Hilbert matrix: [[1. 0.5 0.33333333 0.25 0.2 0.16666667] [0.5 0.33333333 0.25 0.2 0.16666667 0.14285714] [0.33333333 0.25 0.2 0.16666667 0.14285714 0.125 ] [0.25 0.2 0.16666667 0.14285714 0.125 0.11111111] [0.2 0.16666667 0.14285714 0.125 0.11111111 0.1 ] [0.16666667 0.14285714 0.125 0.11111111 0.1 0.09090909]] |