com.imsl.math
Class Matrix

java.lang.Object
  com.imsl.math.Matrix

public class Matrix

extends Object

Matrix manipulation functions.

See Also:

Example

Method Summary

static double[][]	add(double[][] a, double[][] b) Add two rectangular arrays, a + b.
static void	checkMatrix(double[][] a) Check that all of the rows in the matrix have the same length.
static void	checkSquareMatrix(double[][] a) Check that the matrix is square.
static double	frobeniusNorm(double[][] a) Return the Frobenius norm of a matrix.
static double	infinityNorm(double[][] a) Return the infinity norm of a matrix.
static double[]	multiply(double[][] a, double[] x) Multiply the rectangular array a and the column array x.
static double[][]	multiply(double[][] a, double[][] b) Multiply two rectangular arrays, a * b.
static double[]	multiply(double[] x, double[][] a) Return the product of the row array x and the rectangular array a.
static double	oneNorm(double[][] a) Return the matrix one norm.
static double[][]	subtract(double[][] a, double[][] b) Subtract two rectangular arrays, a - b.
static double[][]	transpose(double[][] a) Return the transpose of a matrix.

Methods inherited from class java.lang.Object

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

Method Detail

add

public static double[][] add(double[][] a,
                             double[][] b)

Add two rectangular arrays, a + b.

Parameters:

a - a double rectangular array

b - a double rectangular array

Returns:

a double rectangular array representing the matrix sum of the two arguments

Throws:

IllegalArgumentException - This exception is thrown when (1) the lengths of the rows of either of the input matrices are not uniform, or (2) the matrices are not the same size.

checkMatrix

public static void checkMatrix(double[][] a)

Check that all of the rows in the matrix have the same length.

Parameters:

a - a double matrix

Throws:

IllegalArgumentException - This exception is thrown when the lengths of the rows of the input matrix are not uniform.

checkSquareMatrix

public static void checkSquareMatrix(double[][] a)

Check that the matrix is square.

Parameters:

a - a double matrix

Throws:

IllegalArgumentException - This exception is thrown when the matrix is not square.

frobeniusNorm

public static double frobeniusNorm(double[][] a)

Return the Frobenius norm of a matrix.

Parameters:

a - a double rectangular array

Returns:

a double scalar value equal to the Frobenius norm of the matrix.

infinityNorm

public static double infinityNorm(double[][] a)

Return the infinity norm of a matrix.

Parameters:

a - a double rectangular array

Returns:

a double scalar value equal to the maximum of the row sums of the absolute values of the array elements

multiply

public static double[] multiply(double[][] a,
                                double[] x)

Multiply the rectangular array a and the column array x.

Parameters:

a - a double rectangular matrix

x - a double column array

Returns:

a double vector representing the product of the arguments, a*x

Throws:

IllegalArgumentException - This exception is thrown when (1) the lengths of the rows of the input matrix are not uniform, or (2) the number of columns in the input matrix is not equal to the number of elements in the input column vector.

multiply

public static double[][] multiply(double[][] a,
                                  double[][] b)

Multiply two rectangular arrays, a * b.

Parameters:

a - a double rectangular array

b - a double rectangular array

Returns:

the double matrix product of a times b

Throws:

IllegalArgumentException - This exception is thrown when (1) the lengths of the rows of either of the input matrices are not uniform, or (2) the number of columns in a is not equal to the number of rows in b.

multiply

public static double[] multiply(double[] x,
                                double[][] a)

Return the product of the row array x and the rectangular array a.

Parameters:

x - a double row array

a - a double rectangular matrix

Returns:

a double matrix representing the product of the arguments, x*a.

Throws:

IllegalArgumentException - This exception is thrown when (1) the lengths of the rows of the input matrix are not uniform, or (2) the number of elements in the input vector is not equal to the number of rows of the matrix.

oneNorm

public static double oneNorm(double[][] a)

Return the matrix one norm.

Parameters:

a - a double rectangular array

Returns:

a double value equal to the maximum of the column sums of the absolute values of the array elements

subtract

public static double[][] subtract(double[][] a,
                                  double[][] b)

Subtract two rectangular arrays, a - b.

Parameters:

a - a double rectangular array

b - a double rectangular array

Returns:

a double rectangular array representing the matrix difference of the two arguments

Throws:

IllegalArgumentException - This exception is thrown when (1) the lengths of the rows of either of the input matrices are not uniform, or (2) the matrices are not the same size.

transpose

public static double[][] transpose(double[][] a)

Return the transpose of a matrix.

Parameters:

a - a double matrix

Returns:

a double matrix which is the transpose of the argument

Throws:

IllegalArgumentException - This exception is thrown when the lengths of the rows of the input matrix are not uniform.