Added Symbolics class

Some tests now passing!

src/main/java/no/birkett/kiwi/Constraint.java

@@ -22,8 +22,8 @@ public class Constraint {
         this.strength = Strength.clip(strength);
     }
 
-    public Constraint(Constraint other, RelationalOperator op) {
-        this(other.expression, other.op, other.strength);
+    public Constraint(Constraint other, double strength) {
+        this(other.expression, other.op, strength);
     }
 
     public Expression getExpression() {
@@ -38,8 +38,9 @@ public class Constraint {
         return strength;
     }
 
-    public void setStrength(double strength) {
+    public Constraint setStrength(double strength) {
         this.strength = strength;
+        return this;
     }
 
     public RelationalOperator getOp() {

src/main/java/no/birkett/kiwi/Expression.java

@@ -36,6 +36,10 @@ public class Expression {
         this.constant = constant;
     }
 
+    public Expression(List<Term> terms) {
+        this(terms, 0);
+    }
+
     public double getConstant() {
         return constant;
     }

src/main/java/no/birkett/kiwi/Symbolics.java

@@ -0,0 +1,410 @@
+package no.birkett.kiwi;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Created by alex on 31/01/15.
+ */
+public class Symbolics {
+
+    private Symbolics() {
+    }
+
+    // Variable multiply, divide, and unary invert
+    public static Term multiply(Variable variable, double coefficient) {
+        return new Term(variable, coefficient);
+    }
+
+    public static Term divide(Variable variable, double denominator) {
+        return multiply(variable, (1.0 / denominator));
+    }
+
+    public static Term negate(Variable variable) {
+        return multiply(variable, -1.0);
+    }
+
+    // Term multiply, divide, and unary invert
+    public static Term multiply(Term term, double coefficient) {
+        return new Term(term.getVariable(), term.getCoefficient() * coefficient);
+    }
+
+    public static Term divide(Term term, double denominator) {
+        return multiply(term, (1.0 / denominator));
+    }
+
+    public static Term negate(Term term) {
+        return multiply(term, -1.0);
+    }
+
+    // Expression multiply, divide, and unary invert
+    public static Expression multiply(Expression expression, double coefficient) {
+
+        List<Term> terms = new ArrayList<Term>();
+        
+        for (Term term : expression.getTerms()) {
+            terms.add(multiply(term, coefficient));
+        }
+
+        // TODO Do we need to make a copy of the term objects in the array?
+        return new Expression(terms, expression.getConstant() * coefficient);
+    }
+
+    public static Expression divide(Expression expression, double denominator) {
+        return multiply(expression, (1.0 / denominator));
+    }
+
+
+    public static Expression negate(Expression expression) {
+        return multiply(expression, -1.0);
+    }
+
+    // Double multiply
+    public static Expression multiply(double coefficient, Expression expression) {
+        return multiply(expression, coefficient);
+    }
+
+
+    public static Term multiply(double coefficient, Term term) {
+        return multiply(term, coefficient);
+    }
+
+
+    public static Term multiply(double coefficient, Variable variable) {
+        return multiply(variable, coefficient);
+    }
+
+    // Expression add and subtract
+    public static Expression add(Expression first, Expression second) {
+        //TODO do we need to copy term objects?
+        List<Term> terms = new ArrayList<Term>(first.getTerms().size() + second.getTerms().size());
+
+        terms.addAll(first.getTerms());
+        terms.addAll(second.getTerms());
+
+        return new Expression(terms, first.getConstant() + second.getConstant());
+    }
+
+    public static Expression add(Expression first, Term second) {
+        //TODO do we need to copy term objects?
+        List<Term> terms = new ArrayList<Term>(first.getTerms().size() + 1);
+
+        terms.addAll(first.getTerms());
+        terms.add(second);
+
+        return new Expression(terms, first.getConstant());
+    }
+
+    public static Expression add(Expression expression, Variable variable) {
+        return add(expression, new Term(variable));
+    }
+
+    public static Expression add(Expression expression, double constant) {
+        return new Expression(expression.getTerms(), expression.getConstant() + constant);
+    }
+
+    public static Expression subtract(Expression first, Expression second) {
+        return add(first, negate(second));
+    }
+
+    public static Expression subtract(Expression expression, Term term) {
+        return add(expression, negate(term));
+    }
+
+    public static Expression subtract(Expression expression, Variable variable) {
+        return add(expression, negate(variable));
+    }
+
+    public static Expression subtract(Expression expression, double constant) {
+        return add(expression, -constant);
+    }
+
+    // Term add and subtract
+    public static Expression add(Term term, Expression expression) {
+        return add(expression, term);
+    }
+
+    public static Expression add(Term first, Term second) {
+        List<Term> terms = new ArrayList<Term>(2);
+        terms.add(first);
+        terms.add(second);
+        return new Expression(terms);
+    }
+
+    public static Expression add(Term term, Variable variable) {
+        return add(term, new Term(variable));
+    }
+
+    public static Expression add(Term term, double constant) {
+        return new Expression(term, constant);
+    }
+
+    public static Expression subtract(Term term, Expression expression) {
+        return add(negate(expression), term);
+    }
+
+    public static Expression subtract(Term first, Term second) {
+        return add(first, negate(second));
+    }
+
+    public static Expression subtract(Term term, Variable variable) {
+        return add(term, negate(variable));
+    }
+
+    public static Expression subtract(Term term, double constant) {
+        return add(term, -constant);
+    }
+
+    // Variable add and subtract
+    public static Expression add(Variable variable, Expression expression) {
+        return add(expression, variable);
+    }
+
+    public static Expression add(Variable variable, Term term) {
+        return add(term, variable);
+    }
+
+    public static Expression add(Variable first, Variable second) {
+        return add(new Term(first), second);
+    }
+
+    public static Expression add(Variable variable, double constant) {
+        return add(new Term(variable), constant);
+    }
+
+    public static Expression subtract(Variable variable, Expression expression) {
+        return add(variable, negate(expression));
+    }
+
+    public static Expression subtract(Variable variable, Term term) {
+        return add(variable, negate(term));
+    }
+
+    public static Expression subtract(Variable first, Variable second) {
+        return add(first, negate(second));
+    }
+
+    public static Expression subtract(Variable variable, double constant) {
+        return add(variable, -constant);
+    }
+
+    // Double add and subtract
+
+    public static Expression add(double constant, Expression expression) {
+        return add(expression, constant);
+    }
+
+    public static Expression add(double constant, Term term) {
+        return add(term, constant);
+    }
+
+    public static Expression add(double constant, Variable variable) {
+        return add(variable, constant);
+    }
+
+    public static Expression subtract(double constant, Expression expression) {
+        return add(negate(expression), constant);
+    }
+
+    public static Expression subtract(double constant, Term term) {
+        return add(negate(term), constant);
+    }
+
+    public static Expression subtract(double constant, Variable variable) {
+        return add(negate(variable), constant);
+    }
+
+    // Expression relations
+    public static Constraint equals(Expression first, Expression second) {
+        return new Constraint(subtract(first, second), RelationalOperator.OP_EQ);
+    }
+
+    public static Constraint equals(Expression expression, Term term) {
+        return equals(expression, new Expression(term));
+    }
+
+    public static Constraint equals(Expression expression, Variable variable) {
+        return equals(expression, new Term(variable));
+    }
+
+    public static Constraint equals(Expression expression, double constant) {
+        return equals(expression, new Expression(constant));
+    }
+
+    public static Constraint lessThanOrEqualTo(Expression first, Expression second) {
+        return new Constraint(subtract(first, second), RelationalOperator.OP_LE);
+    }
+
+    public static Constraint lessThanOrEqualTo(Expression expression, Term term) {
+        return lessThanOrEqualTo(expression, new Expression(term));
+    }
+
+    public static Constraint lessThanOrEqualTo(Expression expression, Variable variable) {
+        return lessThanOrEqualTo(expression, new Term(variable));
+    }
+
+    public static Constraint lessThanOrEqualTo(Expression expression, double constant) {
+        return lessThanOrEqualTo(expression, new Expression(constant));
+    }
+
+    public static Constraint greaterThanOrEqualTo(Expression first, Expression second) {
+        return new Constraint(subtract(first, second), RelationalOperator.OP_GE);
+    }
+
+    public static Constraint greaterThanOrEqualTo(Expression expression, Term term) {
+        return greaterThanOrEqualTo(expression, new Expression(term));
+    }
+
+    public static Constraint greaterThanOrEqualTo(Expression expression, Variable variable) {
+        return greaterThanOrEqualTo(expression, new Term(variable));
+    }
+
+    public static Constraint greaterThanOrEqualTo(Expression expression, double constant) {
+        return greaterThanOrEqualTo(expression, new Expression(constant));
+    }
+
+    // Term relations
+    public static Constraint equals(Term term, Expression expression) {
+        return equals(expression, term);
+    }
+
+    public static Constraint equals(Term first, Term second) {
+        return equals(new Expression(first), second);
+    }
+
+    public static Constraint equals(Term term, Variable variable) {
+        return equals(new Expression(term), variable);
+    }
+
+    public static Constraint equals(Term term, double constant) {
+        return equals(new Expression(term), constant);
+    }
+
+    public static Constraint lessThanOrEqualTo(Term term, Expression expression) {
+        return lessThanOrEqualTo(expression, term);
+    }
+
+    public static Constraint lessThanOrEqualTo(Term first, Term second) {
+        return lessThanOrEqualTo(new Expression(first), second);
+    }
+
+    public static Constraint lessThanOrEqualTo(Term term, Variable variable) {
+        return lessThanOrEqualTo(new Expression(term), variable);
+    }
+
+    public static Constraint lessThanOrEqualTo(Term term, double constant) {
+        return lessThanOrEqualTo(new Expression(term), constant);
+    }
+
+    public static Constraint greaterThanOrEqualTo(Term term, Expression expression) {
+        return greaterThanOrEqualTo(expression, term);
+    }
+
+    public static Constraint greaterThanOrEqualTo(Term first, Term second) {
+        return greaterThanOrEqualTo(new Expression(first), second);
+    }
+
+    public static Constraint greaterThanOrEqualTo(Term term, Variable variable) {
+        return greaterThanOrEqualTo(new Expression(term), variable);
+    }
+
+    public static Constraint greaterThanOrEqualTo(Term term, double constant) {
+        return greaterThanOrEqualTo(new Expression(term), constant);
+    }
+
+    // Variable relations
+    public static Constraint equals(Variable variable, Expression expression) {
+        return equals(expression, variable);
+    }
+
+    public static Constraint equals(Variable variable, Term term) {
+        return equals(term, variable);
+    }
+
+    public static Constraint equals(Variable first, Variable second) {
+        return equals(new Term(first), second);
+    }
+
+    public static Constraint equals(Variable variable, double constant) {
+        return equals(new Term(variable), constant);
+    }
+
+    public static Constraint lessThanOrEqualTo(Variable variable, Expression expression) {
+        return lessThanOrEqualTo(expression, variable);
+    }
+
+    public static Constraint lessThanOrEqualTo(Variable variable, Term term) {
+        return lessThanOrEqualTo(term, variable);
+    }
+
+    public static Constraint lessThanOrEqualTo(Variable first, Variable second) {
+        return lessThanOrEqualTo(new Term(first), second);
+    }
+
+    public static Constraint lessThanOrEqualTo(Variable variable, double constant) {
+        return lessThanOrEqualTo(new Term(variable), constant);
+    }
+
+    public static Constraint greaterThanOrEqualTo(Variable variable, Expression expression) {
+        return greaterThanOrEqualTo(expression, variable);
+    }
+
+    public static Constraint greaterThanOrEqualTo(Variable variable, Term term) {
+        return greaterThanOrEqualTo(term, variable);
+    }
+
+    public static Constraint greaterThanOrEqualTo(Variable first, Variable second) {
+        return greaterThanOrEqualTo(new Term(first), second);
+    }
+
+    public static Constraint greaterThanOrEqualTo(Variable variable, double constant) {
+        return greaterThanOrEqualTo(new Term(variable), constant);
+    }
+
+    // Double relations
+    public static Constraint equals(double constant, Expression expression) {
+        return equals(expression, constant);
+    }
+
+    public static Constraint equals(double constant, Term term) {
+        return equals(term, constant);
+    }
+
+    public static Constraint equals(double constant, Variable variable) {
+        return equals(variable, constant);
+    }
+
+    public static Constraint lessThanOrEqualTo(double constant, Expression expression) {
+        return lessThanOrEqualTo(expression, constant);
+    }
+
+    public static Constraint lessThanOrEqualTo(double constant, Term term) {
+        return lessThanOrEqualTo(term, constant);
+    }
+
+    public static Constraint lessThanOrEqualTo(double constant, Variable variable) {
+        return lessThanOrEqualTo(variable, constant);
+    }
+
+    public static Constraint greaterThanOrEqualTo(double constant, Expression expression) {
+        return greaterThanOrEqualTo(expression, constant);
+    }
+
+    public static Constraint greaterThanOrEqualTo(double constant, Term term) {
+        return greaterThanOrEqualTo(term, constant);
+    }
+
+    public static Constraint greaterThanOrEqualTo(double constant, Variable variable) {
+        return greaterThanOrEqualTo(variable, constant);
+    }
+
+    // Constraint strength modifier
+    public static Constraint modifyStrength(Constraint constraint, double strength) {
+        return new Constraint(constraint, strength);
+    }
+
+    public static Constraint modifyStrength(double strength, Constraint constraint) {
+        return modifyStrength(strength, constraint);
+    }
+
+}

src/main/java/no/birkett/kiwi/Variable.java

@@ -14,7 +14,6 @@ public class Variable {
     }
 
     public Variable(double value) {
-
     }
     
     public double getValue() {
@@ -25,11 +24,4 @@ public class Variable {
         this.value = value;
     }
 
-    public Expression times(double value) {
-        return null;
-    }
-
-    public Expression plus(double value) {
-        return null;
-    }
 }

src/test/java/no/birkett/kiwi/Tests.java

@@ -10,36 +10,73 @@ public class Tests {
     private static double EPSILON = 1.0e-8;
 
     @Test
-    public void testKiwi() throws UnsatisfiableConstraintException, DuplicateConstraintException {
+    public void simpleNew() throws UnsatisfiableConstraintException, DuplicateConstraintException {
+        Solver solver = new Solver();
+        Variable x = new Variable("x");
+
+
+        solver.addConstraint(Symbolics.equals(Symbolics.add(x,2), 20));
+
+        solver.updateVariables();
+
+        assertEquals(x.getValue(), 18, EPSILON);
+    }
+    
+    @Test
+    public void simple0() throws UnsatisfiableConstraintException, DuplicateConstraintException {
         Solver solver = new Solver();
         Variable x = new Variable("x");
         Variable y = new Variable("y");
 
+        // x = 20
+        solver.addConstraint(Symbolics.equals(x, 20));
 
-        Term term = new Term(x);
+        // x + 2 == y + 10
+        //
+        solver.addConstraint(Symbolics.equals(Symbolics.add(x,2), Symbolics.add(y, 10)));
 
-        Expression expression = new Expression(term);
-
-        Constraint constraint = new Constraint(expression, RelationalOperator.OP_EQ);
-
-        solver.addConstraint(constraint);
         solver.updateVariables();
+        
+        System.out.println("x " + x.getValue() + " y " + y.getValue());
+
+        assertEquals(y.getValue(), 12, EPSILON);
+        assertEquals(x.getValue(), 20, EPSILON);
     }
     
-    /*@Test
-    public void simple1() {
-        Variable x = new Variable(167);
-        Variable y = new Variable(2);
-        Solver solver = new Solver();
-
-        Constraint eq = new Constraint(x, Constraint.Operator.EQ, new Expression(y));
-        //ClLinearEquation eq = new ClLinearEquation(x, new ClLinearExpression(y));
-        solver.addConstraint(eq);
-        assertEquals(x.value(), y.value(), EPSILON);
-    }
-
-
     @Test
+    public void simple1() throws DuplicateConstraintException, UnsatisfiableConstraintException {
+        Variable x = new Variable("x");
+        Variable y = new Variable("y");
+        Solver solver = new Solver();
+        solver.addConstraint(Symbolics.equals(x, y));
+        solver.updateVariables();
+        assertEquals(x.getValue(), y.getValue(), EPSILON);
+    }
+
+    @Test
+    public void casso1() throws DuplicateConstraintException, UnsatisfiableConstraintException {
+        Variable x = new Variable("x");
+        Variable y = new Variable("y");
+        Solver solver = new Solver();
+
+        solver.addConstraint(Symbolics.lessThanOrEqualTo(x, y));
+        solver.addConstraint(Symbolics.equals(y, Symbolics.add(x, 3.0)));
+        solver.addConstraint(Symbolics.equals(x, 10.0).setStrength(Strength.WEAK));
+        solver.addConstraint(Symbolics.equals(y, 10.0).setStrength(Strength.WEAK));
+
+        solver.updateVariables();
+        
+        if (Math.abs(x.getValue() - 10.0) < EPSILON) {
+            assertEquals(10, x.getValue(), EPSILON);
+            assertEquals(13, y.getValue(), EPSILON);
+        } else {
+            assertEquals(7, x.getValue(), EPSILON);
+            assertEquals(10, y.getValue(), EPSILON);
+        }
+    }
+
+
+    /*@Test
     public void addDelete1() {
         Variable x = new Variable("x");
         Solver solver = new Solver();
@@ -112,25 +149,7 @@ public class Tests {
         assertEquals(120, y.value(), EPSILON);
     }
 
-    @Test
-    public void casso1() {
-        Variable x = new Variable("x");
-        Variable y = new Variable("y");
-        Solver solver = new Solver();
 
-        solver.addConstraint(new Constraint(x, Constraint.Operator.LEQ, y));
-        solver.addConstraint(new Constraint(y, Constraint.Operator.EQ, x.plus(3.0)));
-        solver.addConstraint(new Constraint(x, Constraint.Operator.EQ, 10.0, Strength.WEAK));
-        solver.addConstraint(new Constraint(y, Constraint.Operator.EQ, 10.0, Strength.WEAK));
-
-        if (Math.abs(x.getValue() - 10.0) < EPSILON) {
-            assertEquals(10, x.value(), EPSILON);
-            assertEquals(13, y.value(), EPSILON);
-        } else {
-            assertEquals(7, x.value(), EPSILON);
-            assertEquals(10, y.value(), EPSILON);
-        }
-    }
 
     @Test(expected = RequiredFailure.class)
     public void inconsistent1() throws InternalError {