com.stata.sfi

Class Matrix

java.lang.Object

com.stata.sfi.Matrix

public final class Matrix
extends Object

This class provides access to Stata matrices. All methods are not thread-safe unless otherwise stated.

Example:

	public static int printMatrix(String args[]) {
		String name = args[0];
		double[] matrix = Matrix.getMatrix(name);
		int cols = Matrix.getMatrixCol(name);
		int rows = Matrix.getMatrixRow(name);

		if (cols == 0 || rows == 0) {
			SFIToolkit.errorln("Empty matrix");
			return 503;
		}
		for (int i = 0; i < rows; i++) {
			for (int j = 0; j < cols; j++) {
				double element = Matrix.getAt(matrix, cols, i, j);
				SFIToolkit.displayln("[" + (i + 1) + ", " + (j + 1) + "] = "
						+ element);
			}
		}
		return 0;
	}

Method Summary

Modifier and Type	Method and Description
static int	convertSymmetricToStd(String name) Convert a symmetric matrix to a standard matrix.
static int	createMatrix(String name, int rows, int cols, double initialValue) Create a Stata matrix.
static int	createMatrix(String name, int rows, int cols, double initialValue, boolean isSymmetric) Create a Stata matrix.
static double	getAt(double[] matrix, int colCount, int row, int col) Access an element of a previously obtained Stata matrix in the form of a one-dimensional array.
static double[]	getMatrix(String name) Get the data in a Stata matrix.
static int	getMatrixCol(String name) Get the number of columns in a Stata matrix.
static String[]	getMatrixColNames(String name) Get the column names of a Stata matrix.
static int	getMatrixRow(String name) Get the number of rows in a Stata matrix.
static String[]	getMatrixRowNames(String name) Get the row names of a Stata matrix.
static int	setMatrixColNames(String name, String[] colNames) Set the column names of a Stata matrix.
static int	setMatrixRowNames(String name, String[] rowNames) Set the row names of a Stata matrix.
static int	storeMatrixAt(String name, int row, int col, double val) Store an element in an existing Stata matrix.

Methods inherited from class java.lang.Object

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

Method Detail

getMatrix

public static double[] getMatrix(String name)

Get the data in a Stata matrix. Use getAt() to obtain elements of the returned array.

Parameters:

name - Name of the Stata matrix.

Returns:

A double array containing the matrix values. Returns null if an error occurs.

getAt

public static double getAt(double[] matrix,
                           int colCount,
                           int row,
                           int col)

Access an element of a previously obtained Stata matrix in the form of a one-dimensional array.

Parameters:

matrix - The matrix in the form of a one-dimensional array.

colCount - The number of columns. This value can be obtained by calling getMatrixCol().

row - Zero-based row number.

col - Zero-based column number.

Returns:

The element.

getMatrixRow

public static int getMatrixRow(String name)

Get the number of rows in a Stata matrix.

Parameters:

name - Name of the Stata matrix.

Returns:

The number of rows. Returns -1 if an error occurs.

getMatrixCol

public static int getMatrixCol(String name)

Get the number of columns in a Stata matrix.

Parameters:

name - Name of the Stata matrix.

Returns:

The number of columns. Returns -1 if an error occurs.

getMatrixRowNames

public static String[] getMatrixRowNames(String name)

Get the row names of a Stata matrix.

Parameters:

name - Name of the Stata matrix.

Returns:

A String array containing the row names of the matrix. Returns null if an error occurs.

getMatrixColNames

public static String[] getMatrixColNames(String name)

Get the column names of a Stata matrix.

Parameters:

name - Name of the Stata matrix.

Returns:

A String array containing the column names of the matrix. Returns null if an error occurs.

setMatrixRowNames

public static int setMatrixRowNames(String name,
                                    String[] rowNames)

Set the row names of a Stata matrix.

Parameters:

name - Name of the Stata matrix.

rowNames - A String array containing the row names for the matrix. The array length must match the number of rows in the matrix.

Returns:

Return code from Stata; 0 if successful.

setMatrixColNames

public static int setMatrixColNames(String name,
                                    String[] colNames)

Set the column names of a Stata matrix.

Parameters:

name - Name of the Stata matrix.

colNames - A String array containing the column names for the matrix. The array length must match the number of columns in the matrix.

Returns:

Return code from Stata; 0 if successful.

createMatrix

public static int createMatrix(String name,
                               int rows,
                               int cols,
                               double initialValue)

Create a Stata matrix.

Parameters:

name - Name of the matrix to create.

rows - Number of rows.

cols - Number of columns.

initialValue - An initialization value for each element.

Returns:

Return code from Stata; 0 if successful.

createMatrix

public static int createMatrix(String name,
                               int rows,
                               int cols,
                               double initialValue,
                               boolean isSymmetric)

Create a Stata matrix.

Parameters:

name - Name of the matrix to create.

rows - Number of rows.

cols - Number of columns.

initialValue - An initialization value for each element.

isSymmetric - Mark the matrix as symmetric. If the number of rows and columns are not equal, this parameter will be ignored. This parameter affects the behavior of storeMatrixAt(). When the matrix is marked as symmetric, storeMatrixAt() will always maintain symmetry.

Returns:

Return code from Stata; 0 if successful.

storeMatrixAt

public static int storeMatrixAt(String name,
                                int row,
                                int col,
                                double val)

Store an element in an existing Stata matrix.

Parameters:

name - Name of the matrix.

row - Zero-based row number.

col - Zero-based column number.

val - Value.

Returns:

Return code from Stata; 0 if successful.

convertSymmetricToStd

public static int convertSymmetricToStd(String name)

Convert a symmetric matrix to a standard matrix. If the matrix is not symmetric, then nothing is done.

Parameters:

name - Name of the matrix.

Returns:

Return code from Stata; 0 if successful.