org.ejml.ops

Class CMatrixFeatures

java.lang.Object

org.ejml.ops.CMatrixFeatures

public class CMatrixFeatures
extends java.lang.Object

Functions for computing the features of complex matrices

Constructor Summary

Constructors

Constructor and Description
CMatrixFeatures()

Method Summary

Modifier and Type	Method and Description
static boolean	hasNaN(CD1Matrix64F m) Checks to see if any element in the matrix is NaN.
static boolean	hasUncountable(CD1Matrix64F m) Checks to see if any element in the matrix is NaN of Infinite.
static boolean	isEquals(CD1Matrix64F a, CD1Matrix64F b) Checks to see if each element in the two matrices are equal: aij == bij
static boolean	isEquals(CD1Matrix64F a, CD1Matrix64F b, double tol) Checks to see if each element in the two matrices are within tolerance of each other: tol ≥ |aij - bij|.
static boolean	isHermitian(CDenseMatrix64F Q, double tol) Hermitian matrix is a square matrix with complex entries that is equal to its own conjugate transpose.
static boolean	isIdentical(CD1Matrix64F a, CD1Matrix64F b, double tol) Checks to see if each corresponding element in the two matrices are within tolerance of each other or have the some symbolic meaning.
static boolean	isIdentity(ComplexMatrix64F mat, double tol) Checks to see if the provided matrix is within tolerance to an identity matrix.
static boolean	isPositiveDefinite(CDenseMatrix64F A) Checks to see if the matrix is positive definite.
static boolean	isUnitary(CDenseMatrix64F Q, double tol) Unitary matrices have the following properties: Q*QH = I

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CMatrixFeatures

public CMatrixFeatures()

Method Detail

hasNaN

public static boolean hasNaN(CD1Matrix64F m)

Checks to see if any element in the matrix is NaN.

Parameters:

m - A matrix. Not modified.

Returns:

True if any element in the matrix is NaN.

hasUncountable

public static boolean hasUncountable(CD1Matrix64F m)

Checks to see if any element in the matrix is NaN of Infinite.

Parameters:

m - A matrix. Not modified.

Returns:

True if any element in the matrix is NaN of Infinite.

isEquals

public static boolean isEquals(CD1Matrix64F a,
                               CD1Matrix64F b)

Checks to see if each element in the two matrices are equal: a_ij == b_ij

NOTE: If any of the elements are NaN then false is returned. If two corresponding elements are both positive or negative infinity then they are equal.

Parameters:

a - A matrix. Not modified.

b - A matrix. Not modified.

Returns:

true if identical and false otherwise.

isEquals

public static boolean isEquals(CD1Matrix64F a,
                               CD1Matrix64F b,
                               double tol)

Checks to see if each element in the two matrices are within tolerance of each other: tol ≥ |a_ij - b_ij|.

NOTE: If any of the elements are not countable then false is returned.
NOTE: If a tolerance of zero is passed in this is equivalent to calling isEquals(org.ejml.data.CD1Matrix64F, org.ejml.data.CD1Matrix64F)

Parameters:

a - A matrix. Not modified.

b - A matrix. Not modified.

tol - How close to being identical each element needs to be.

Returns:

true if equals and false otherwise.

isIdentical

public static boolean isIdentical(CD1Matrix64F a,
                                  CD1Matrix64F b,
                                  double tol)

Checks to see if each corresponding element in the two matrices are within tolerance of each other or have the some symbolic meaning. This can handle NaN and Infinite numbers.

If both elements are countable then the following equality test is used:
|a_ij - b_ij| ≤ tol.
Otherwise both numbers must both be Double.NaN, Double.POSITIVE_INFINITY, or Double.NEGATIVE_INFINITY to be identical.

Parameters:

a - A matrix. Not modified.

b - A matrix. Not modified.

tol - Tolerance for equality.

Returns:

true if identical and false otherwise.

isIdentity

public static boolean isIdentity(ComplexMatrix64F mat,
                                 double tol)

Checks to see if the provided matrix is within tolerance to an identity matrix.

Parameters:

mat - Matrix being examined. Not modified.

tol - Tolerance.

Returns:

True if it is within tolerance to an identify matrix.

isHermitian

public static boolean isHermitian(CDenseMatrix64F Q,
                                  double tol)

Hermitian matrix is a square matrix with complex entries that is equal to its own conjugate transpose.

Parameters:

Q - The matrix being tested. Not modified.

tol - Tolerance.

Returns:

True if it passes the test.

isUnitary

public static boolean isUnitary(CDenseMatrix64F Q,
                                double tol)

Unitary matrices have the following properties:

Q*Q^H = I

This is the complex equivalent of orthogonal matrix.

Parameters:

Q - The matrix being tested. Not modified.

tol - Tolerance.

Returns:

True if it passes the test.

isPositiveDefinite

public static boolean isPositiveDefinite(CDenseMatrix64F A)

Checks to see if the matrix is positive definite.

x^T A x > 0
for all x where x is a non-zero vector and A is a hermitian matrix.

Parameters:

A - square hermitian matrix. Not modified.

Returns:

True if it is positive definite and false if it is not.