AdjacencyBackedSparseMatrix.java

package util;

import gnu.trove.TIntFloatHashMap;

public class AdjacencyBackedSparseMatrix {
	
	TIntFloatHashMap[] matrix;
	float threshold;

	public AdjacencyBackedSparseMatrix(float thres, int n) {
		matrix = new TIntFloatHashMap[n];
		for (int i=0; i<n; i++)
			matrix[i] = new TIntFloatHashMap();
		this.threshold = thres;
	}

	public void set(int x, int y, float value) {
		if (value < threshold)
			return;
		matrix[x].put(y, value);
	}

	//upper triangle matrix
	public float get(int x, int y) {
		if (x <= y){
			return matrix[x].get(y);
		}
		return matrix[y].get(x);
	}

}