public static NumericVariable operator /(NumericVariable v, double d)
{
NumericVariable result = v.DeriveVariable("Prop/rh", $".{v.VarIndex}/{d}");
ProportionalConstraint.CreateProportionalConstraint(d, result, v);
return(result);
}
public static NumericVariable operator -(NumericVariable v)
{
NumericVariable result = v.DeriveVariable("Invrh", $"-.{v.VarIndex}");
IsInverseConstraint.CreateIsInverseConstraint(v, result);
return(result);
}
public static NumericVariable operator -(NumericVariable left, NumericVariable right)
{
NumericVariable result = left.DeriveVariable("+Sum0rh", $".{left.VarIndex}-.{right.VarIndex}");
SumIs0Constraint.CreateSumIs0Constraint(-left, right, result);
return(result);
}
public SimpleConstraintSolver(double eps = 1.0 / 1024.0 / 1024.0 / 1024.0)
{
Eps = eps;
ZERO = CreateConstant("0", 0);
ONE = CreateConstant("1", 1);
NEGATIVE_INF = CreateConstant("-inf", double.NegativeInfinity);
POSITIVE_INF = CreateConstant("+inf", double.PositiveInfinity);
}
protected override bool Update(NumericVariable v)
{
if (v == _variable1)
{
return(_variable1.RestrictRange(_variable2.Value.Lo, _variable2.Value.Hi, 1 / _d));
}
else
{
return(_variable2.RestrictRange(_variable1.Value.Lo, _variable1.Value.Hi, _d));
}
}
protected override bool Update(NumericVariable v)
{
if (v == _variable1)
{
// v1 >= v2
return(_variable1.RestrictRange(_variable2.Value.Lo, double.PositiveInfinity));
}
else
{
// v2 <= v1
return(_variable2.RestrictRange(double.NegativeInfinity, _variable1.Value.Hi));
}
}
internal NumericVariable GetOrCreateVariable([NotNull] string shortName, [NotNull] string definition, double?lo, double?hi, float interpolate)
{
if (_solved)
{
throw new InvalidOperationException($"Solver is solved - no new variable '{shortName}', please! (definition='{definition}')");
}
NumericVariable result;
if (!_allVariables.TryGetValue(definition, out result))
{
_allVariables.Add(definition, result = new NumericVariable(shortName, definition, this, lo, hi, interpolate));
}
return(result);
}
protected override bool Update(NumericVariable v)
{
return(v.RestrictRange(_range));
}
private AtLeastConstraint(NumericVariable variable1, NumericVariable variable2) : base(variable1, variable2)
{
}
public static AtLeastConstraint CreateAtLeastConstraint(NumericVariable variable1, NumericVariable variable2)
{
return(new AtLeastConstraint(variable1, variable2));
}
protected override bool Update(NumericVariable v)
{
return(v.RestrictRange(-(v == _variable1 ? _variable2 : _variable1).Value));
}
/// <summary>
/// The variable's value is restricted to be equal to the (eventual) value of another variable.
/// </summary>
/// <returns><c>this</c></returns>
public NumericVariable Set(NumericVariable value)
{
EqualityConstraint.CreateEqualityConstraint(this, value);
return(this);
}
public VariableVector MaxY(NumericVariable value)
{
_y.Max(value);
return(this);
}
public VariableVector MinY(NumericVariable value)
{
_y.Min(value);
return(this);
}
protected abstract bool Update(NumericVariable v);
/// <summary>
/// The variable's maximum is restricted to the (eventual) value of another variable.
/// </summary>
/// <returns><c>this</c></returns>
public NumericVariable Max(NumericVariable value)
{
AtLeastConstraint.CreateAtLeastConstraint(value, this);
return(this);
}
public static ProportionalConstraint CreateProportionalConstraint(double d, NumericVariable variable1, NumericVariable variable2)
{
return(new ProportionalConstraint(d, variable1, variable2));
}
private RangeConstraint(NumericVariable inputVariable, Range range) : base(inputVariable)
{
_range = range;
}
public static RangeConstraint CreateRangeConstraint(NumericVariable inputVariable, Range range)
{
return(new RangeConstraint(inputVariable, range));
}
protected UnaryConstraint([NotNull] NumericVariable inputVariable) : base(inputVariable)
{
_inputVariable = inputVariable;
}
private ProportionalConstraint(double d, NumericVariable variable1, NumericVariable variable2) : base(variable1, variable2)
{
_d = d;
}
protected BinaryConstraint([NotNull] NumericVariable variable1, [NotNull] NumericVariable variable2) : base(variable1, variable2)
{
_variable1 = variable1;
_variable2 = variable2;
}
//public SumIs0Constraint Plus(DoubleHolder d) {
// return new SumIs0Constraint(_plus.Concat(new[] { d }));
//}
protected override bool Update(NumericVariable v)
{
bool changed = false;
// The following propagation uses these ideas:
// For each variable v, take the sum S of all OTHER Lo values. A high value that is higher
// than -S will never cancel S to zero, let alone sums that are greater than S. Hence,
// v.Hi can be restricted to <= -S.
// Likewise, v.Lo can be restricted to >= -S where S is the sum of all other Hi values.
// O(n^2) algorithm - a O(n) algorithm is possible ... later
double loSum = 0;
// OnceExcluded is necessary for a constraint like X + X + Y = 0: When we already know
// that X = [100..100] and Y = [-200..-200], this should succeed. However, when during
// Upgrade(X) we skip both X's (via w != v), the sum will not be 100-200 == 100, but
// -200; and hence
// X will then be restricted to [200..+inf], which, together with the previously known
// value X = 100 will erroneously imply that there is no solution for X.
// By the way, when in X + X + Y = 0, we have X = [-inf...+inf] and Y = [-200..-200] at
// the beginning, we will NOT conclude that X = [100..100] - that would be equation
// solving, which we do not support at this level.
bool onceExcluded = false;
foreach (var w in _inputVariables)
{
if (onceExcluded || w != v)
{
double wLo = w.Value.Lo;
if (double.IsNegativeInfinity(wLo))
{
// Nothing can be said about the sum of lows - cancel this computation;
goto SKIP_LO;
}
loSum += wLo;
}
else
{
onceExcluded = true;
}
}
changed |= v.RestrictRange(double.NegativeInfinity, -loSum);
SKIP_LO:
double hiSum = 0;
onceExcluded = false;
foreach (var w in _inputVariables)
{
if (onceExcluded || w != v)
{
double wHi = w.Value.Hi;
if (double.IsPositiveInfinity(wHi))
{
// Nothing can be said about the sum of his - cancel this computation;
goto SKIP_HI;
}
hiSum += wHi;
}
else
{
onceExcluded = true;
}
}
changed |= v.RestrictRange(-hiSum, double.PositiveInfinity);
SKIP_HI:
return(changed);
}
public static EqualityConstraint CreateEqualityConstraint(NumericVariable variable1, NumericVariable variable2)
{
return(new EqualityConstraint(variable1, variable2));
}
protected override bool Update(NumericVariable v)
{
throw new NotImplementedException("Update(IEnumerable<NumericVariable>) is overridden");
}
private EqualityConstraint(NumericVariable variable1, NumericVariable variable2) : base(variable1, variable2)
{
}
public VariableVector SetY(NumericVariable value)
{
_y.Set(value);
return(this);
}
public static IsInverseConstraint CreateIsInverseConstraint(NumericVariable variable1, NumericVariable variable2)
{
return(new IsInverseConstraint(variable1, variable2));
}
public VariableVector(string name, [NotNull] NumericVariable x, [NotNull] NumericVariable y)
{
Name = name;
_x = x;
_y = y;
}
private IsInverseConstraint(NumericVariable variable1, NumericVariable variable2) : base(variable1, variable2)
{
}