ucar.ma2

Class MAMatrix

java.lang.Object

ucar.ma2.MAMatrix

public class MAMatrix
extends java.lang.Object

Abstraction for matrix operations. A matrix is a rank-2 Array: m[rows, cols]. All operations done in double precision

Constructor Summary

Constructors

Constructor and Description
MAMatrix(Array a) Create an MAMatrix using the given rank-2 array.
MAMatrix(int nrows, int ncols) Create an MAMatrix of the given shape.

Method Summary

Modifier and Type	Method and Description
MAVector	column(int j) Get the jth column, return as a MAVector: same backing store.
MAMatrix	copy() Create a new MAMatrix that is the same as this one, with a copy of the backing store.
MAVector	dot(MAVector v) Dot product of matrix and vector: return M dot v
double	getDouble(int i, int j)
int	getNcols()
int	getNrows()
static MAMatrix	multiply(MAMatrix m1, MAMatrix m2) Matrix multiply: return m1 * m2.
void	postMultiplyDiagonal(MAVector diag) Matrix multiply by a diagonal matrix, store result in this: this = this * diag
void	preMultiplyDiagonal(MAVector diag) Matrix multiply by a diagonal matrix, store result in this: this = diag * this
MAVector	row(int i) Get the ith row, return as a MAVector: same backing store.
void	setDouble(int i, int j, double val)
MAMatrix	transpose() Create a MAMatrix that is the transpose of this one, with the same backing store.

Methods inherited from class java.lang.Object

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

Constructor Detail

MAMatrix

public MAMatrix(int nrows,
                int ncols)

Create an MAMatrix of the given shape.

Parameters:

nrows - number of rows

ncols - number of cols

MAMatrix

public MAMatrix(Array a)

Create an MAMatrix using the given rank-2 array.

Parameters:

a - rank-2 array

Throws:

java.lang.IllegalArgumentException - is a is not rank 2

Method Detail

getNrows

public int getNrows()

getNcols

public int getNcols()

getDouble

public double getDouble(int i,
                        int j)

setDouble

public void setDouble(int i,
                      int j,
                      double val)

copy

public MAMatrix copy()

Create a new MAMatrix that is the same as this one, with a copy of the backing store.

transpose

public MAMatrix transpose()

Create a MAMatrix that is the transpose of this one, with the same backing store. Use copy() to get a copy.

column

public MAVector column(int j)

Get the jth column, return as a MAVector: same backing store.

row

public MAVector row(int i)

Get the ith row, return as a MAVector: same backing store.

dot

public MAVector dot(MAVector v)

Dot product of matrix and vector: return M dot v

Parameters:

v - dot product with this vector

Returns:

MAVector result: new vector

Throws:

java.lang.IllegalArgumentException - if ncols != v.getSize().

multiply

public static MAMatrix multiply(MAMatrix m1,
                                MAMatrix m2)

Matrix multiply: return m1 * m2.

Parameters:

m1 - left matrix

m2 - right matrix

Returns:

MAMatrix result: new matrix

Throws:

java.lang.IllegalArgumentException - if m1.getNcols() != m2.getNrows().

postMultiplyDiagonal

public void postMultiplyDiagonal(MAVector diag)

Matrix multiply by a diagonal matrix, store result in this: this = this * diag

Parameters:

diag - diagonal matrix stored as a Vector

Throws:

java.lang.IllegalArgumentException - if ncols != diag.getNelems().

preMultiplyDiagonal

public void preMultiplyDiagonal(MAVector diag)

Matrix multiply by a diagonal matrix, store result in this: this = diag * this

Parameters:

diag - diagonal matrix stored as a Vector

Throws:

java.lang.IllegalArgumentException - if nrows != diag.getNelems().