SparseMatrix.SparseArray (JMSL Numerical Library)

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JMSL^TM Numerical Library 6.1

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com.imsl.math
Class SparseMatrix.SparseArray

java.lang.Object
  com.imsl.math.SparseMatrix.SparseArray

Enclosing class:: SparseMatrix

public static class SparseMatrix.SparseArray
extends Object
extends Object

The SparseArray class uses public fields to hold the data for a sparse matrix in the Java Sparse Array format. This format came about as a means for storing sparse matrices in Java. In this format, a sparse matrix is represented by two arrays of arrays. One array contains the references to the nonzero value arrays for each row of the sparse matrix. The other contains the references to the associated column index arrays.

As an example, consider the following real sparse matrix:

$A=begin{pmatrix} 10.0 & 0.0 & 0.0 & 0.0 & 0.0 & 0.0 \ 0.0 & 10.0 & -3.0 & -1.0 & 0.0 & 0.0 \ 0.0 & 0.0 & 15.0 & 0.0 & 0.0 & 0.0 \ -2.0 & 0.0 & 0.0 & 10.0 & -1.0 & 0.0 \ -1.0 & 0.0 & 0.0 & -5.0 & 1.0 & -3.0 \ -1.0 & -2.0 & 0.0 & 0.0 & 0.0 & 6.0 end{pmatrix}$

In SparseArray, this matrix can be represented by the two jagged arrays, values and index, where values refers to the nonzero entries in A and index to the column indices:

double values[][] = {
          {10.0},
          {10.0, -3.0, -1.0},
          {15.0},
          {-2.0, 10.0, -1.0}, 
          {-1.0, -5.0, 1.0, -3.0},
          {-1.0, -2.0, 6.0}
       }

int index[][] = {
          {0}, 
          {1, 2, 3},
          {2},
          {0, 3, 4},
          {0, 3, 4, 5},
          {0, 1, 5}
      }

Field Summary
`int[][]`	`index` Jagged array containing column indices.
`int`	`numberOfColumns` Number of columns in the matrix.
`long`	`numberOfNonZeros` Number of nonzeros in the matrix.
`int`	`numberOfRows` Number of rows in the matrix.
`double[][]`	`values` Jagged array containing sparse array values.

Constructor Summary
`SparseMatrix.SparseArray()`

Method Summary

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Field Detail

index

public int[][] index

Jagged array containing column indices. The length of this array equals numberOfRows. The length of each row equals the number of nonzeros in that row of the sparse matrix.

numberOfColumns

public int numberOfColumns

Number of columns in the matrix.

numberOfNonZeros

public long numberOfNonZeros

Number of nonzeros in the matrix.

numberOfRows

public int numberOfRows

Number of rows in the matrix.

values

public double[][] values

Jagged array containing sparse array values. This array must have the same shape as index.

Constructor Detail