SparseSquareMatrix (biojava 5.2.0 API)

java.lang.Object
- org.biojava.nbio.structure.math.SparseSquareMatrix

All Implemented Interfaces:

Serializable
```
public class SparseSquareMatrix
extends Object
implements Serializable
```
A sparse, square matrix, implementing using two arrays of sparse vectors, one representation for the rows and one for the columns. For matrix-matrix product, we might also want to store the column representation. Derived from http://introcs.cs.princeton.edu/java/44st/SparseMatrix.java.html For additional documentation, see Section 4.4 of Introduction to Programming in Java: An Interdisciplinary Approach by Robert Sedgewick and Kevin Wayne.

See Also:

Serialized Form

Constructor Summary

Constructors
Constructor Description

SparseSquareMatrix(int N)
initialize an N-by-N matrix of all 0s

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`double`	`get(int i, int j)`	access a value at i,j
`int`	`nnz()`	return the number of nonzero entries (not the most efficient implementation)
`SparseSquareMatrix`	`plus(SparseSquareMatrix B)`	return C = A + B
`void`	`put(int i, int j, double value)`	set A[i][j] = value
`SparseVector`	`times(SparseVector x)`
`String`	`toString()`

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

- Constructor Detail
  - SparseSquareMatrix
```
public SparseSquareMatrix(int N)
```
    initialize an N-by-N matrix of all 0s
    
    Parameters:
    
    N - - size
- Method Detail
  - put
```
public void put(int i,
                int j,
                double value)
```
    set A[i][j] = value
    
    Parameters:
    
    i -
    
    j -
    
    value -
  - get
```
public double get(int i,
                  int j)
```
    access a value at i,j
    
    Parameters:
    
    i -
    
    j -
    
    Returns:
    
    return A[i][j]
  - nnz
```
public int nnz()
```
    return the number of nonzero entries (not the most efficient implementation)
    
    Returns:
  - times
```
public SparseVector times(SparseVector x)
```
    Parameters:
    
    x -
    
    Returns:
    
    return the matrix-vector product b = Ax
  - plus
```
public SparseSquareMatrix plus(SparseSquareMatrix B)
```
    return C = A + B
    
    Parameters:
    
    B -
    
    Returns:
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object