Files
wscience/src/math/matrix/Symmetric.java

105 lines
2.7 KiB
Java

package math.matrix;
import exception.IllegalDimensionException;
import math.Sequence;
/**
* Symmetric matrix object d<sub>ij</sub>=d<sub>ji</sub>&isin;&#x211D;
* with n rows and n columns
* @author Daniel Weschke
*/
public class Symmetric extends Matrix {
/**
* UID
*/
private static final long serialVersionUID = -3506578822884073555L;
public Symmetric(int n){
this.m = n;
this.n = n;
data = new double[Sequence.triangularNumber(n)];
}
public Symmetric(double... d){
this((int)Math.ceil(Sequence.triangularRoot(d.length)));
int i;
for(i=0; i<d.length; i++)
set(i, d[i]);
}
public Matrix set(int i, double d){
data[i] = d;
return this;
}
public Matrix set(int i, int j, double d){
data[index(i,j)] = d;
return this;
}
public double get(int i, int j){
return get(index(i,j));
}
private int index(int i, int j){
return i>j?Sequence.triangularNumber(i)+j:i+Sequence.triangularNumber(j);
}
/**
* Adds two matrices of the same dimension (entrywise addition).
* The addition of two n-by-n matrices <b>A</b> and <b>B</b>,
* is again an n-by-n matrix computed by adding corresponding elements.
* @param B matrix
* @return <b>C</b> = <b>A</b> + <b>B</b>, entrywise summarized matrix
* @throws IllegalDimensionException
*/
public Matrix plus(Matrix B) throws IllegalDimensionException{
checkDimensions(B);
int i,j;
Matrix c = createAddition(B);
c.newOperation();
if(B instanceof Diagonal)
for(i=0; i<m; i++)
for(j=i; j<n; j++){
c.set(i, j, get(i,j)+((Diagonal) B).get(i));
c.operate();
}
else if(B instanceof Symmetric)
for(i=0; i<m; i++)
for(j=i; j<n; j++){
c.set(i,j, get(i,j)+B.get(i,j));
c.operate();
}
else
for(i=0; i<m; i++)
for(j=0; j<n; j++){
c.set(i,j, get(i,j)+B.get(i,j));
c.operate();
}
// System.out.println(this instanceof Symmetric);
// System.out.println(B instanceof Symmetric);
return c;
}
public static void main(String[] args){
Symmetric s1 = new Symmetric(1.);
System.out.println(s1);
Symmetric s2 = new Symmetric(1., 2.);
System.out.println(s2);
Symmetric s3 = new Symmetric(1., 2., 3.);
System.out.println(s3);
Symmetric s4 = new Symmetric(1., 2., 3., 4.);
System.out.println(s4);
System.out.println(s4.get(0,2));
System.out.println(s4.get(2,0));
try {
System.out.println(s2.plus(s3));
System.out.println("Operations: "+s2.plus(s3).getOperationsTotal());
System.out.println(s2.minus(s3));
} catch (IllegalDimensionException e) {
e.printStackTrace();
}
}
}