cern.colt.function.DoubleDoubleFunction Java Examples

/**
 * Demonstrates usage of this class.
 */
public static void demo1() {
	cern.jet.math.Functions F = cern.jet.math.Functions.functions;
	double a = 0.5; 
	double b = 0.2;
	double v = Math.sin(a) + Math.pow(Math.cos(b),2);
	System.out.println(v);
	DoubleDoubleFunction f = F.chain(F.plus,F.sin,F.chain(F.square,F.cos));
	//DoubleDoubleFunction f = F.chain(plus,sin,F.chain(square,cos));
	System.out.println(f.apply(a,b));
	DoubleDoubleFunction g = new DoubleDoubleFunction() {
		public final double apply(double x, double y) { return Math.sin(x) + Math.pow(Math.cos(y),2); }
	};
	System.out.println(g.apply(a,b));
	DoubleFunction m = F.plus(3);
	DoubleFunction n = F.plus(4);
	System.out.println(m.apply(0));
	System.out.println(n.apply(0));
}
 

/**
 * Demonstrates usage of this class.
 */
public static void demo1() {
	cern.jet.math.Functions F = cern.jet.math.Functions.functions;
	double a = 0.5; 
	double b = 0.2;
	double v = Math.sin(a) + Math.pow(Math.cos(b),2);
	System.out.println(v);
	DoubleDoubleFunction f = F.chain(F.plus,F.sin,F.chain(F.square,F.cos));
	//DoubleDoubleFunction f = F.chain(plus,sin,F.chain(square,cos));
	System.out.println(f.apply(a,b));
	DoubleDoubleFunction g = new DoubleDoubleFunction() {
		public final double apply(double x, double y) { return Math.sin(x) + Math.pow(Math.cos(y),2); }
	};
	System.out.println(g.apply(a,b));
	DoubleFunction m = F.plus(3);
	DoubleFunction n = F.plus(4);
	System.out.println(m.apply(0));
	System.out.println(n.apply(0));
}
 

/**
 * Constructs a function that returns <tt>a + b*constant</tt>.
 * <tt>a</tt> and <tt>b</tt> are variables, <tt>constant</tt> is fixed.
 */
public static DoubleDoubleFunction plusMult(double constant) {
	return new PlusMult(constant); 
	/*
	return new DoubleDoubleFunction() {
		public final double apply(double a, double b) { return a + b*constant; }
	};
	*/
}
 

/**
 * Constructs a function that returns <tt>a + b*constant</tt>.
 * <tt>a</tt> and <tt>b</tt> are variables, <tt>constant</tt> is fixed.
 */
public static DoubleDoubleFunction plusMult(double constant) {
	return new PlusMult(constant); 
	/*
	return new DoubleDoubleFunction() {
		public final double apply(double a, double b) { return a + b*constant; }
	};
	*/
}
 

/**
 * Benchmarks and demonstrates usage of trivial and complex functions.
 */
public static void demo2(int size) {
	cern.jet.math.Functions F = cern.jet.math.Functions.functions;
	System.out.println("\n\n");
	double a = 0.0; 
	double b = 0.0;
	double v = Math.abs(Math.sin(a) + Math.pow(Math.cos(b),2));
	//double v = Math.sin(a) + Math.pow(Math.cos(b),2);
	//double v = a + b;
	System.out.println(v);
	
	//DoubleDoubleFunction f = F.chain(F.plus,F.identity,F.identity);
	DoubleDoubleFunction f = F.chain(F.abs,F.chain(F.plus,F.sin,F.chain(F.square,F.cos)));
	//DoubleDoubleFunction f = F.chain(F.plus,F.sin,F.chain(F.square,F.cos));
	//DoubleDoubleFunction f = F.plus;
	
	System.out.println(f.apply(a,b));
	DoubleDoubleFunction g = new DoubleDoubleFunction() {
		public final double apply(double x, double y) { return Math.abs(Math.sin(x) + Math.pow(Math.cos(y),2)); }
		//public final double apply(double x, double y) { return x+y; }
	};
	System.out.println(g.apply(a,b));

	// emptyLoop
	cern.colt.Timer emptyLoop = new cern.colt.Timer().start();
	a = 0; b = 0;
	double sum = 0;
	for (int i=size; --i >= 0; ) {
		sum += a;
		a++;
		b++;
	}
	emptyLoop.stop().display();
	System.out.println("empty sum="+sum);
	
	cern.colt.Timer timer = new cern.colt.Timer().start();
	a = 0; b = 0;
	sum = 0;
	for (int i=size; --i >= 0; ) {
		sum += Math.abs(Math.sin(a) + Math.pow(Math.cos(b),2));
		//sum += a + b;
		a++; b++;
	}
	timer.stop().display();
	System.out.println("evals / sec = "+size / timer.minus(emptyLoop).seconds());
	System.out.println("sum="+sum);

	timer.reset().start();
	a = 0; b = 0;
	sum = 0;
	for (int i=size; --i >= 0; ) {
		sum += f.apply(a,b);
		a++; b++;
	}
	timer.stop().display();
	System.out.println("evals / sec = "+size / timer.minus(emptyLoop).seconds());
	System.out.println("sum="+sum);
		
	timer.reset().start();
	a = 0; b = 0;
	sum = 0;
	for (int i=size; --i >= 0; ) {
		sum += g.apply(a,b);
		a++; b++;
	}
	timer.stop().display();
	System.out.println("evals / sec = "+size / timer.minus(emptyLoop).seconds());
	System.out.println("sum="+sum);
		
}
 

/**
 * Benchmarks and demonstrates usage of trivial and complex functions.
 */
public static void demo2(int size) {
	cern.jet.math.Functions F = cern.jet.math.Functions.functions;
	System.out.println("\n\n");
	double a = 0.0; 
	double b = 0.0;
	double v = Math.abs(Math.sin(a) + Math.pow(Math.cos(b),2));
	//double v = Math.sin(a) + Math.pow(Math.cos(b),2);
	//double v = a + b;
	System.out.println(v);
	
	//DoubleDoubleFunction f = F.chain(F.plus,F.identity,F.identity);
	DoubleDoubleFunction f = F.chain(F.abs,F.chain(F.plus,F.sin,F.chain(F.square,F.cos)));
	//DoubleDoubleFunction f = F.chain(F.plus,F.sin,F.chain(F.square,F.cos));
	//DoubleDoubleFunction f = F.plus;
	
	System.out.println(f.apply(a,b));
	DoubleDoubleFunction g = new DoubleDoubleFunction() {
		public final double apply(double x, double y) { return Math.abs(Math.sin(x) + Math.pow(Math.cos(y),2)); }
		//public final double apply(double x, double y) { return x+y; }
	};
	System.out.println(g.apply(a,b));

	// emptyLoop
	cern.colt.Timer emptyLoop = new cern.colt.Timer().start();
	a = 0; b = 0;
	double sum = 0;
	for (int i=size; --i >= 0; ) {
		sum += a;
		a++;
		b++;
	}
	emptyLoop.stop().display();
	System.out.println("empty sum="+sum);
	
	cern.colt.Timer timer = new cern.colt.Timer().start();
	a = 0; b = 0;
	sum = 0;
	for (int i=size; --i >= 0; ) {
		sum += Math.abs(Math.sin(a) + Math.pow(Math.cos(b),2));
		//sum += a + b;
		a++; b++;
	}
	timer.stop().display();
	System.out.println("evals / sec = "+size / timer.minus(emptyLoop).seconds());
	System.out.println("sum="+sum);

	timer.reset().start();
	a = 0; b = 0;
	sum = 0;
	for (int i=size; --i >= 0; ) {
		sum += f.apply(a,b);
		a++; b++;
	}
	timer.stop().display();
	System.out.println("evals / sec = "+size / timer.minus(emptyLoop).seconds());
	System.out.println("sum="+sum);
		
	timer.reset().start();
	a = 0; b = 0;
	sum = 0;
	for (int i=size; --i >= 0; ) {
		sum += g.apply(a,b);
		a++; b++;
	}
	timer.stop().display();
	System.out.println("evals / sec = "+size / timer.minus(emptyLoop).seconds());
	System.out.println("sum="+sum);
		
}
 

public void normalize() {
	// System.out.println(adjacencyMatrix);
	int adjacencyMatrixSize = adjacencyMatrix.columns();
	
	if(adjacencyMatrixSize < 1)
		return;

	DoubleMatrix2D selector = new SparseDoubleMatrix2D(1, adjacencyMatrixSize);
	selector.set(0, 0, 1.0);
	// System.out.println(selector);
	// get vertices reachable from V0
	int cardinality = selector.cardinality();
	int lastCardinality = 0;

	DoubleDoubleFunction merge = new DoubleDoubleFunction() {
		public double apply(double a, double b) { 
			return (a > 0 || b > 0) ? 1 : 0; 
		}
	};

	while(cardinality != lastCardinality) {
		lastCardinality = cardinality;
		// selector = Algebra.DEFAULT.mult(selector, adjacencyMatrix);
		selector.assign(Algebra.DEFAULT.mult(selector, adjacencyMatrix), merge);
		// System.out.println(selector);
		cardinality = selector.cardinality();
	}

	// System.out.println(selector);

	if(cardinality == adjacencyMatrixSize) {
		return;
	}

	// IntArrayList nonZeros = new IntArrayList();
	// IntArrayList unusedInt = new IntArrayList();
	// DoubleArrayList unusedDouble = new DoubleArrayList();
	// selector.getNonZeros(unusedInt, nonZeros, unusedDouble);
	// SparseDoubleMatrix2D reduced = new SparseDoubleMatrix2D(adjacencyMatrix.viewSelection(nonZeros.elements(), nonZeros.elements()).toArray());

	SparseDoubleMatrix2D reduced = new SparseDoubleMatrix2D(cardinality, cardinality);
	int iCurrentVertex = 0;
	for(int i=0; i<adjacencyMatrixSize; ++i) {
		if(selector.get(0, i) != 0.0) {
			int jCurrentVertex = 0;
			for(int j=0; j<adjacencyMatrixSize; ++j) {
				if(selector.get(0, j) != 0.0){
					reduced.set(iCurrentVertex, jCurrentVertex, adjacencyMatrix.get(i, j));
					++jCurrentVertex;
				}
			}
			++iCurrentVertex;
		}
	}
	// System.out.println(reduced);
	// System.out.println("=======");
	adjacencyMatrix = reduced;
	vertexCount = adjacencyMatrix.columns();
	edgeCount = adjacencyMatrix.cardinality();
}
 

public void normalize() {
	// System.out.println(adjacencyMatrix);
	int adjacencyMatrixSize = adjacencyMatrix.columns();

	if(adjacencyMatrixSize < 1)
		return;

	DoubleMatrix2D selector = new SparseDoubleMatrix2D(1, adjacencyMatrixSize);
	selector.set(0, 0, 1.0);
	// System.out.println(selector);
	// get vertices reachable from V0
	int cardinality = selector.cardinality();
	int lastCardinality = 0;

	DoubleDoubleFunction merge = new DoubleDoubleFunction() {
		public double apply(double a, double b) { 
			return (a > 0 || b > 0) ? 1 : 0; 
		}
	};

	while(cardinality != lastCardinality) {
		lastCardinality = cardinality;
		// selector = Algebra.DEFAULT.mult(selector, adjacencyMatrix);
		selector.assign(Algebra.DEFAULT.mult(selector, adjacencyMatrix), merge);
		// System.out.println(selector);
		cardinality = selector.cardinality();
	}

	// System.out.println(selector);

	if(cardinality == adjacencyMatrixSize) {
		return;
	}

	// IntArrayList nonZeros = new IntArrayList();
	// IntArrayList unusedInt = new IntArrayList();
	// DoubleArrayList unusedDouble = new DoubleArrayList();
	// selector.getNonZeros(unusedInt, nonZeros, unusedDouble);
	// SparseDoubleMatrix2D reduced = new SparseDoubleMatrix2D(adjacencyMatrix.viewSelection(nonZeros.elements(), nonZeros.elements()).toArray());

	SparseDoubleMatrix2D reduced = new SparseDoubleMatrix2D(cardinality, cardinality);
	int iCurrentVertex = 0;
	for(int i=0; i<adjacencyMatrixSize; ++i) {
		if(selector.get(0, i) != 0.0) {
			int jCurrentVertex = 0;
			for(int j=0; j<adjacencyMatrixSize; ++j) {
				if(selector.get(0, j) != 0.0){
					reduced.set(iCurrentVertex, jCurrentVertex, adjacencyMatrix.get(i, j));
					++jCurrentVertex;
				}
			}
			++iCurrentVertex;
		}
	}
	// System.out.println(reduced);
	// System.out.println("=======");
	adjacencyMatrix = reduced;
	vertexCount = adjacencyMatrix.columns();
	edgeCount = adjacencyMatrix.cardinality();
}
 

/**
 * Constructs a function that returns <tt>function.apply(b,a)</tt>, i.e. applies the function with the first operand as second operand and the second operand as first operand.
 * 
 * @param function a function taking operands in the form <tt>function.apply(a,b)</tt>.
 * @return the binary function <tt>function(b,a)</tt>.
 */
public static DoubleDoubleFunction swapArgs(final DoubleDoubleFunction function) {
	return new DoubleDoubleFunction() {
		public final double apply(double a, double b) { return function.apply(b,a); }
	};
}
 

/**
 * Constructs a unary function from a binary function with the first operand (argument) fixed to the given constant <tt>c</tt>.
 * The second operand is variable (free).
 * 
 * @param function a binary function taking operands in the form <tt>function.apply(c,var)</tt>.
 * @return the unary function <tt>function(c,var)</tt>.
 */
public static DoubleFunction bindArg1(final DoubleDoubleFunction function, final double c) {
	return new DoubleFunction() {
		public final double apply(double var) { return function.apply(c,var); }
	};
}
 

/**
 * Constructs a function that returns <tt>a - b*constant</tt>.
 * <tt>a</tt> and <tt>b</tt> are variables, <tt>constant</tt> is fixed.
 */
public static DoubleDoubleFunction minusMult(final double constant) {
	return plusMult(-constant);
}
 

/**
 * Constructs the function <tt>g( h(a,b) )</tt>.
 * 
 * @param g a unary function.
 * @param h a binary function.
 * @return the unary function <tt>g( h(a,b) )</tt>.
 */
public static DoubleDoubleFunction chain(final DoubleFunction g, final DoubleDoubleFunction h) {
	return new DoubleDoubleFunction() {
		public final double apply(double a, double b) { return g.apply(h.apply(a,b)); }
	};
}
 

/**
 * Constructs the function <tt>f( g(a), h(b) )</tt>.
 * 
 * @param f a binary function.
 * @param g a unary function.
 * @param h a unary function.
 * @return the binary function <tt>f( g(a), h(b) )</tt>.
 */
public static DoubleDoubleFunction chain(final DoubleDoubleFunction f, final DoubleFunction g, final DoubleFunction h) {
	return new DoubleDoubleFunction() {
		public final double apply(double a, double b) { return f.apply(g.apply(a), h.apply(b)); }
	};
}
 

/**
 * Constructs a unary function from a binary function with the second operand (argument) fixed to the given constant <tt>c</tt>.
 * The first operand is variable (free).
 * 
 * @param function a binary function taking operands in the form <tt>function.apply(var,c)</tt>.
 * @return the unary function <tt>function(var,c)</tt>.
 */
public static DoubleFunction bindArg2(final DoubleDoubleFunction function, final double c) {
	return new DoubleFunction() {
		public final double apply(double var) { return function.apply(var,c); }
	};
}
 

/**
 * Constructs a unary function from a binary function with the first operand (argument) fixed to the given constant <tt>c</tt>.
 * The second operand is variable (free).
 * 
 * @param function a binary function taking operands in the form <tt>function.apply(c,var)</tt>.
 * @return the unary function <tt>function(c,var)</tt>.
 */
public static DoubleFunction bindArg1(final DoubleDoubleFunction function, final double c) {
	return new DoubleFunction() {
		public final double apply(double var) { return function.apply(c,var); }
	};
}
 

/**
 * Constructs a function that returns <tt>function.apply(b,a)</tt>, i.e. applies the function with the first operand as second operand and the second operand as first operand.
 * 
 * @param function a function taking operands in the form <tt>function.apply(a,b)</tt>.
 * @return the binary function <tt>function(b,a)</tt>.
 */
public static DoubleDoubleFunction swapArgs(final DoubleDoubleFunction function) {
	return new DoubleDoubleFunction() {
		public final double apply(double a, double b) { return function.apply(b,a); }
	};
}
 

/**
 * Constructs a function that returns <tt>a - b*constant</tt>.
 * <tt>a</tt> and <tt>b</tt> are variables, <tt>constant</tt> is fixed.
 */
public static DoubleDoubleFunction minusMult(final double constant) {
	return plusMult(-constant);
}
 

/**
 * Constructs the function <tt>g( h(a,b) )</tt>.
 * 
 * @param g a unary function.
 * @param h a binary function.
 * @return the unary function <tt>g( h(a,b) )</tt>.
 */
public static DoubleDoubleFunction chain(final DoubleFunction g, final DoubleDoubleFunction h) {
	return new DoubleDoubleFunction() {
		public final double apply(double a, double b) { return g.apply(h.apply(a,b)); }
	};
}
 

/**
 * Constructs the function <tt>f( g(a), h(b) )</tt>.
 * 
 * @param f a binary function.
 * @param g a unary function.
 * @param h a unary function.
 * @return the binary function <tt>f( g(a), h(b) )</tt>.
 */
public static DoubleDoubleFunction chain(final DoubleDoubleFunction f, final DoubleFunction g, final DoubleFunction h) {
	return new DoubleDoubleFunction() {
		public final double apply(double a, double b) { return f.apply(g.apply(a), h.apply(b)); }
	};
}
 

/**
 * Constructs a unary function from a binary function with the second operand (argument) fixed to the given constant <tt>c</tt>.
 * The first operand is variable (free).
 * 
 * @param function a binary function taking operands in the form <tt>function.apply(var,c)</tt>.
 * @return the unary function <tt>function(var,c)</tt>.
 */
public static DoubleFunction bindArg2(final DoubleDoubleFunction function, final double c) {
	return new DoubleFunction() {
		public final double apply(double var) { return function.apply(var,c); }
	};
}