/// <summary>
/// Generates a test file
/// </summary>
static void GenerateExamples()
{
FileStream fs = new FileStream("examples.hl", FileMode.Create);
StreamWriter w = new StreamWriter(fs);
Random rnd = new Random(2);
// Dependencies
w.WriteLine("needs \"test_explicit.hl\"");
w.WriteLine("let test = [");
for (int k = 0; k < 300; k++)
{
List <decimal> cs = new List <decimal>();
List <string> vars = new List <string>();
int i = rnd.Next(100);
while (i >= 0)
{
vars.Add('x'.ToString() + "_" + String.Format("{0:000}", i));
cs.Add(rnd.Next(1000000000));
i -= rnd.Next(10) + 1;
}
LinearFunction f = new LinearFunction(cs, vars);
w.Write(f.ToHOLExplicit(5, null));
// w.Write("`" + f.ToHOLString(5) + "`");
w.WriteLine(";");
}
w.WriteLine("];;");
w.Flush();
fs.Close();
}
/// <summary>
/// Private constructor
/// </summary>
private Inequality(Label id, IneqType type, LinearFunction lhs, LpNumber rhs, bool negFlag)
{
this.Id = id;
this.type = type;
this.lhs = lhs;
this.rhs = rhs;
this.NegFlag = negFlag;
}
/// <summary>
/// Returns the equality 0 = 0
/// </summary>
public static Inequality Zero()
{
Label id = new Label("ZERO", "");
LinearFunction lhs = new LinearFunction(new List <decimal>(), new List <string>());
LpNumber rhs = new LpNumber(0);
Inequality ineq = new Inequality(id, IneqType.Eq, lhs, rhs, false);
return(ineq);
}
public static LinearFunction operator *(decimal n, LinearFunction f)
{
LinearFunction result = new LinearFunction();
foreach (var term in f.terms)
{
result.terms.Add(term * n);
}
return(result);
}
/// <summary>
/// Rounds down the linear function
/// </summary>
/// <param name="precision"></param>
/// <returns></returns>
public LinearFunction RoundDown(int precision)
{
LinearFunction f = new LinearFunction();
foreach (var term in terms)
{
f.terms.Add(term.RoundDown(precision));
}
return(f);
}
/// <summary>
/// Addition
/// </summary>
/// <param name="f1"></param>
/// <param name="f2"></param>
/// <returns></returns>
public static LinearFunction operator +(LinearFunction f1, LinearFunction f2)
{
f1.terms.Sort();
f2.terms.Sort();
LinearFunction f = new LinearFunction();
int n1 = f1.terms.Count;
int n2 = f2.terms.Count;
int index1 = 0, index2 = 0;
while (index1 < n1 && index2 < n2)
{
Term t1 = f1.terms[index1];
Term t2 = f2.terms[index2];
int r = t1.CompareTo(t2);
if (r == 0)
{
LpNumber n = t1.c + t2.c;
if (n.value != 0)
{
f.terms.Add(new Term(n, t1.varName));
}
index1++;
index2++;
}
else if (r > 0)
{
f.terms.Add(t2);
index2++;
}
else
{
f.terms.Add(t1);
index1++;
}
}
for (int i = index1; i < n1; i++)
{
f.terms.Add(f1.terms[i]);
}
for (int i = index2; i < n2; i++)
{
f.terms.Add(f2.terms[i]);
}
return(f);
}
/// <summary>
/// Parses an inequality
/// </summary>
/// <param name="scanner"></param>
/// <returns></returns>
public static Inequality ParseInequality(Scanner scanner)
{
Token t;
// Identifier
Label id = Label.ParseLabel(scanner);
// :
t = scanner.nextToken();
if (t.Type != TokenType.Colon)
{
throw new Exception(": expected: " + t);
}
// lhs
LinearFunction lhs = LinearFunction.ParseFunction(scanner);
// type
t = scanner.nextToken();
IneqType type;
switch (t.Type)
{
case TokenType.Le:
type = IneqType.Le;
break;
case TokenType.Ge:
type = IneqType.Ge;
break;
case TokenType.Eq:
type = IneqType.Eq;
break;
default:
throw new Exception("<=, =>, or = expected: " + t);
}
// rhs
t = scanner.nextToken();
if (t.Type != TokenType.Integer && t.Type != TokenType.Double)
{
throw new Exception("A number is expected: " + t);
}
LpNumber rhs = new LpNumber(decimal.Parse(t.StringValue));
return(new Inequality(id, type, lhs, rhs, false));
}
/// <summary>
/// Parses a linear function
/// </summary>
/// <param name="scanner"></param>
/// <returns></returns>
public static LinearFunction ParseFunction(Scanner scanner)
{
LinearFunction f = new LinearFunction();
Token t;
while (true)
{
t = scanner.peekToken();
if (t.Type != TokenType.Plus && t.Type != TokenType.Minus)
{
break;
}
Term term = Term.ParseTerm(scanner);
f.terms.Add(term);
}
return(f);
}
/// <summary>
/// Processes all inequalities based on the given solution
/// </summary>
/// <param name="sol"></param>
/// <param name="precision"></param>
/// <returns></returns>
public bool SetSolution(LPSolution sol, int precision)
{
if (sol.NumberOfVariables != vars.Number)
{
throw new Exception("Inconsistent number of variables");
}
if (sol.NumberOfConstraints != originalIneqs.Count)
{
throw new Exception("Inconsistent number of constraints");
}
ineqs = new List <Inequality>();
// ineqMarginals = new List<LpNumber>();
// Constraints
for (int i = 0; i < sol.NumberOfConstraints; i++)
{
LpNumber m = sol.ConstraintMarginals[i];
if (m.IsZero(precision))
{
continue;
}
Inequality ineq = originalIneqs[i];
if (m.value < 0)
{
ineq = -ineq;
m = -m;
}
ineq = ineq.Round(precision);
ineq.Marginal = m;
ineqs.Add(ineq);
// ineqMarginals.Add(m);
}
// Variables
List <Inequality> tmpIneqs = new List <Inequality>();
for (int i = 0; i < sol.NumberOfVariables; i++)
{
Variable var = vars[i];
LpNumber m = sol.VariableMarginals[i];
if (m.IsZero(precision))
{
continue;
}
Inequality ineq;
if (m.value < 0)
{
var.LMarginal = -m;
ineq = -Inequality.FromLowerBound(var);
ineq = ineq.Round(precision) * (-m.value);
}
else
{
var.UMarginal = m;
ineq = Inequality.FromUpperBound(var);
ineq = ineq.Round(precision) * m.value;
}
tmpIneqs.Add(ineq);
}
// Compute additional inequality
// Inequality sum1 = ineqs[0] * ineqs[0].Marginal.value; //ineqMarginals[0].value;
Inequality sum1 = Inequality.Zero();
for (int i = 0; i < ineqs.Count; i++)
{
sum1 += ineqs[i] * ineqs[i].Marginal.value; //ineqMarginals[i].value;
}
Inequality sum2 = sum1;
for (int i = 0; i < tmpIneqs.Count; i++)
{
sum2 += tmpIneqs[i];
}
// df
LinearFunction df = objective - sum2.lhs;
// Compute corrections for marginals
foreach (var term in df.Terms)
{
LpNumber c = term.c;
if (c.value < 0)
{
vars[term.varName].LMarginal -= c;
}
else
{
vars[term.varName].UMarginal += c;
}
}
// Verification
LpNumber sum = sum1.rhs;
for (int i = 0; i < vars.Number; i++)
{
Variable var = vars[i];
if (!var.LMarginal.IsZero(precision))
{
sum -= var.LMarginal * LpNumber.RoundDown(var.LBound, precision);
}
if (!var.UMarginal.IsZero(precision))
{
sum += var.UMarginal * LpNumber.RoundUp(var.UBound, precision);
}
}
LpNumber eps = sol.UpperBound - sum;
Console.WriteLine("eps = {0}", eps);
if (eps.value < 0)
{
return(false);
}
// Set the upper bound
upperBound = sol.UpperBound;
// Generate inequalities for variables
Console.Write("Generating inequalities for variables...");
varIneqs = new List <Inequality>();
// varIneqMarginals = new List<LpNumber>();
for (int i = 0; i < vars.Number; i++)
{
Variable var = vars[i];
Inequality ineq;
if (!var.LMarginal.IsZero(precision))
{
ineq = -Inequality.FromLowerBound(var);
ineq = ineq.Round(precision);
ineq.Marginal = var.LMarginal;
varIneqs.Add(ineq);
// varIneqMarginals.Add(var.LMarginal);
}
if (!var.UMarginal.IsZero(precision))
{
ineq = Inequality.FromUpperBound(var);
ineq = ineq.Round(precision);
ineq.Marginal = var.UMarginal;
varIneqs.Add(ineq);
// varIneqMarginals.Add(var.UMarginal);
}
}
Console.WriteLine("done");
return(true);
}
/// <summary>
/// Parses a LP
/// </summary>
/// <param name="scanner"></param>
/// <returns></returns>
public static LP ParseLP(Scanner scanner)
{
LP lp = new LP();
// Maximize
Token t = scanner.nextToken();
if (t.Type != TokenType.Identifier && t.StringValue != "Maximize")
{
throw new Exception("Maximize expected: " + t);
}
// objective
t = scanner.nextToken();
if (t.Type != TokenType.Identifier)
{
throw new Exception("Identifier expected: " + t);
}
// :
t = scanner.nextToken();
if (t.Type != TokenType.Colon)
{
throw new Exception(": expected: " + t);
}
// objective function
lp.objective = LinearFunction.ParseFunction(scanner);
// Subject To
t = scanner.nextToken();
if (t.Type != TokenType.Identifier && t.StringValue != "Subject")
{
throw new Exception("Subject To expected: " + t);
}
t = scanner.nextToken();
if (t.Type != TokenType.Identifier && t.StringValue != "To")
{
throw new Exception("Subject To expected: " + t);
}
// Constraints
while (true)
{
t = scanner.peekToken();
if (t.Type == TokenType.Identifier && t.StringValue == "Bounds")
{
break;
}
if (t.Type == TokenType.EOF)
{
break;
}
Inequality ineq = Inequality.ParseInequality(scanner);
lp.originalIneqs.Add(ineq);
}
// Bounds
t = scanner.nextToken();
if (t.Type != TokenType.Identifier && t.StringValue != "Bounds")
{
throw new Exception("Bounds expected: " + t);
}
// Bounds
while (true)
{
t = scanner.peekToken();
if (t.Type == TokenType.Identifier && t.StringValue == "End")
{
break;
}
if (t.Type == TokenType.EOF)
{
break;
}
ParseBound(scanner, lp);
}
return(lp);
}
