Simplex Algorithmus

public class Simplex {

	private double[][] simplexAsArray;
	private int numberOfVariables;


	public Simplex(final double[][] simplexAsArray, final int numberOfVariables) {
		this.simplexAsArray = simplexAsArray;
		this.numberOfVariables = numberOfVariables;
	}


	public double[] solveSimplex() {
		double[] result = new double[numberOfVariables + 1];
		int p;
		int q;

		while (!isFinished()) {
			printSimplex();
			System.out.println 				("-----------------------------------------------------------------------------------------------------");
			p = determineP();
			q = determineQ(p);
			pivot(p, q);
		}
		for (int i = 0; i < numberOfVariables; i++) {
			for (int j = 0; j < simplexAsArray.length; j++) {
				if (simplexAsArray[j][i] == 1.0) {
					result[i] = simplexAsArray[j][simplexAsArray[j].length - 1];
				}
			}
		}
		result[numberOfVariables] = simplexAsArray[0][simplexAsArray[0].length - 1];

		return result;
	}

	private boolean solutionFound() {
		return determineP() == -1;
	}

	private int searchNewPivotElementElementColumn() {
		for (int i = 0; i < simplexAsArray[0].length; i++) {
			if (simplexAsArray[0][i] < 0) {
				return i;
			}
		}

		return -1;
	}

	/**
	 *
	 * This method determines the row the next pivot step.
	 *
	 * @param p the column used for the next pivot step
	 * @return the row used for the next pivot step
	 *
	 */
	private int searchNewPivotElementRow(int p) {
		double max = 0;
		int q = -1;

		for (int i = 1; i < simplexAsArray.length; i++) {
			if (simplexAsArray[i][p] > 0 && (simplexAsArray[i][p] / simplexAsArray[i][simplexAsArray[i].length - 1] > max)) {
				max = simplexAsArray[i][p] / simplexAsArray[i][simplexAsArray[i].length - 1];
				q = i;
			}
		}

		return q;
	}


	private void usePivotElement(int p, int q) {
		for (int j = 0; j < simplexAsArray.length; j++) {
			for (int k = simplexAsArray[0].length - 1; k >= 0; k--) {
				if (j != q && k != p) {
					simplexAsArray[j][k] = simplexAsArray[j][k] - simplexAsArray[q][k] * simplexAsArray[j][p] / simplexAsArray[q][p];
				}
			}
		}
		for (int j = 0; j < simplexAsArray.length; j++) {
			if (j != q) {
				simplexAsArray[j][p] = 0;
			}
		}
		for (int k = 0; k < simplexAsArray[0].length; k++) {
			if (k != p) {
				simplexAsArray[q][k] = simplexAsArray[q][k] / simplexAsArray[q][p];
			}
		}
		simplexAsArray[q][p] = 1;
	}

	private void printSimplex() {
		for (int i = 0; i < simplexAsArray.length; i++) {
			for (int j = 0; j < simplexAsArray[i].length; j++) {
				System.out.print(simplexAsArray[i][j] + " ");
			}
			System.out.println();
		}
	}

}