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/*
* LingPipe v. 4.1.0
* Copyright (C) 2003-2011 Alias-i
*
* This program is licensed under the Alias-i Royalty Free License
* Version 1 WITHOUT ANY WARRANTY, without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the Alias-i
* Royalty Free License Version 1 for more details.
*
* You should have received a copy of the Alias-i Royalty Free License
* Version 1 along with this program; if not, visit
* http://alias-i.com/lingpipe/licenses/lingpipe-license-1.txt or contact
* Alias-i, Inc. at 181 North 11th Street, Suite 401, Brooklyn, NY 11211,
* +1 (718) 290-9170.
*/
package com.aliasi.matrix;
import java.util.Arrays;
/**
* A DenseMatrix is a matrix implementation suitable for
* matrices with primarily non-zero values. The dimensionality of a
* dense matrix is set at construction time and immutable afterwards.
* Values may be specified at construction time or given default
* values; they are mutable and may be reset after construction.
*
* Implementation Note: A dense matrix represents the values
* with a two-dimensional array of primitive double values.
*
* @author Bob Carpenter
* @version 2.4
* @since LingPipe2.0
*/
public class DenseMatrix extends AbstractMatrix {
private final double[][] mValues;
private final int mNumRows;
private final int mNumColumns;
private static final boolean IGNORE = true;
/**
* Construct a dense matrix with the specified positive number of
* rows and columns. All values are initially 0.0.
*
* @param numRows Number of rows for this matrix.
* @param numColumns Number of columns for this matrix.
* @throws IllegalArgumentException If either the number of rows or
* columns is not positive.
*/
public DenseMatrix(int numRows, int numColumns) {
this(zeroValues(numRows,numColumns),IGNORE);
}
/**
* Construct a dense matrix with the specified values. Row
* dimensionality is determined by the dimensionality of the
* specified array of values. Column dimensionality is specified
* as the maximum length of a row of specified values. Shorter
* rows in the specified values are filled with 0.0.
* All labels are initialized to null.
*
* @param values Two-dimensional array of values on which to base
* this matrix.
* @throws IllegalArgumentException If the either dimension of
* the values array is 0.
*/
public DenseMatrix(double[][] values) {
this(copyValues(values),IGNORE);
}
// package protected with dummy arg to distinguish
DenseMatrix(double[][] values,
boolean ignoreMe) {
mValues = values;
mNumRows = values.length;
if (mNumRows < 1) {
String msg = "Require positive number of rows."
+ " Found number of rows=" + mNumRows;
throw new IllegalArgumentException(msg);
}
mNumColumns = values[0].length;
if (mNumColumns < 1) {
String msg = "Require positive number of columns."
+ " Found number of columns=" + mNumColumns;
throw new IllegalArgumentException(msg);
}
}
@Override
public final int numRows() {
return mNumRows;
}
@Override
public final int numColumns() {
return mNumColumns;
}
@Override
public double value(int row, int column) {
return mValues[row][column];
}
@Override
public void setValue(int row, int column, double value) {
mValues[row][column] = value;
}
private static int numColumns(double[][] values) {
int numColumns = 0;
for (int i = 0; i < values.length; ++i)
numColumns = Math.max(numColumns,values[i].length);
return numColumns;
}
private static double[][] copyValues(double[][] values) {
int numRows = values.length;
int numColumns = numColumns(values);
double[][] result = new double[numRows][numColumns];
for (int i = 0; i < numRows; ++i) {
for (int j = 0; j < values[i].length; ++j)
result[i][j] = values[i][j];
for (int j = values[i].length; j < numColumns; ++j)
result[i][j] = 0.0;
}
return result;
}
private static double[][] zeroValues(int numRows, int numColumns) {
double[][] result = new double[numRows][numColumns];
for (int i = 0; i < result.length; ++i)
Arrays.fill(result[i],0.0);
return result;
}
}