/// <summary>
/// Replace var with a symbolic expression expr that is equal to it.
/// If a variable has been added to this expression that wasn't there
/// before, or if a variable has been dropped from this expression
/// because it now has a coefficient of 0, inform the solver.
/// PRECONDITIONS:
/// var occurs with a non-zero coefficient in this expression.
/// </summary>
public /*sealed*/ void SubstituteOut(ClAbstractVariable var, ClLinearExpression expr,
ClAbstractVariable subject, ClTableau solver)
{
if (Trace)
{
FnEnterPrint(string.Format("CLE:SubstituteOut: {0}, {1}, {2}, ...", var, expr, subject));
}
if (Trace)
{
TracePrint("this = " + this);
}
double multiplier = ((ClDouble)_terms[var]).Value;
_terms.Remove(var);
IncrementConstant(multiplier * expr.Constant);
foreach (ClAbstractVariable clv in expr.Terms.Keys)
{
double coeff = ((ClDouble)expr.Terms[clv]).Value;
ClDouble d_old_coeff = (ClDouble)_terms[clv];
if (d_old_coeff != null)
{
double old_coeff = d_old_coeff.Value;
double newCoeff = old_coeff + multiplier * coeff;
if (Cl.Approx(newCoeff, 0.0))
{
solver.NoteRemovedVariable(clv, subject);
_terms.Remove(clv);
}
else
{
d_old_coeff.Value = newCoeff;
}
}
else
{
// did not have that variable already
_terms.Add(clv, new ClDouble(multiplier * coeff));
solver.NoteAddedVariable(clv, subject);
}
}
if (Trace)
{
TracePrint("Now this is " + this);
}
}
/// <summary>
/// Add a term c*v to this expression. If the expression already
/// contains a term involving v, add c to the existing coefficient.
/// If the new coefficient is approximately 0, delete v. Notify the
/// solver if v appears or disappears from this expression.
/// </summary>
public /*sealed*/ ClLinearExpression AddVariable(ClAbstractVariable v, double c,
ClAbstractVariable subject, ClTableau solver)
{
// body largely duplicated above
if (Trace)
{
FnEnterPrint(string.Format("AddVariable: {0}, {1}, {2}, ...", v, c, subject));
}
ClDouble coeff = (ClDouble)_terms[v];
if (coeff != null)
{
double new_coefficient = coeff.Value + c;
if (Cl.Approx(new_coefficient, 0.0))
{
solver.NoteRemovedVariable(v, subject);
_terms.Remove(v);
}
else
{
coeff.Value = new_coefficient;
}
}
else
{
if (!Cl.Approx(c, 0.0))
{
_terms.Add(v, new ClDouble(c));
solver.NoteAddedVariable(v, subject);
}
}
return(this);
}
/// <summary>
/// Replace var with a symbolic expression expr that is equal to it.
/// If a variable has been added to this expression that wasn't there
/// before, or if a variable has been dropped from this expression
/// because it now has a coefficient of 0, inform the solver.
/// PRECONDITIONS:
/// var occurs with a non-zero coefficient in this expression.
/// </summary>
public void SubstituteOut(ClAbstractVariable var, ClLinearExpression expr, ClAbstractVariable subject, ClTableau solver)
{
double multiplier = (_terms[var]).Value;
_terms.Remove(var);
IncrementConstant(multiplier * expr.Constant);
foreach (ClAbstractVariable clv in expr.Terms.Keys)
{
double coeff = (expr.Terms[clv]).Value;
ClDouble dOldCoeff;
if (_terms.TryGetValue(clv, out dOldCoeff))
{
double oldCoeff = dOldCoeff.Value;
double newCoeff = oldCoeff + multiplier * coeff;
if (Approx(newCoeff, 0.0))
{
solver.NoteRemovedVariable(clv, subject);
_terms.Remove(clv);
}
else
{
dOldCoeff.Value = newCoeff;
}
}
else
{
// did not have that variable already
_terms.Add(clv, new ClDouble(multiplier * coeff));
solver.NoteAddedVariable(clv, subject);
}
}
}
/// <summary>
/// Add a term c*v to this expression. If the expression already
/// contains a term involving v, add c to the existing coefficient.
/// If the new coefficient is approximately 0, delete v. Notify the
/// solver if v appears or disappears from this expression.
/// </summary>
public ClLinearExpression AddVariable(ClAbstractVariable v, double c, ClAbstractVariable subject, ClTableau solver)
{
ClDouble coeff = _terms[v];
if (coeff != null)
{
double newCoefficient = coeff.Value + c;
if (Approx(newCoefficient, 0.0))
{
solver.NoteRemovedVariable(v, subject);
_terms.Remove(v);
}
else
{
coeff.Value = newCoefficient;
}
}
else
{
if (!Approx(c, 0.0))
{
_terms.Add(v, new ClDouble(c));
solver.NoteAddedVariable(v, subject);
}
}
return(this);
}
/// <summary>
/// Add n*expr to this expression from another expression expr.
/// Notify the solver if a variable is added or deleted from this
/// expression.
/// </summary>
public ClLinearExpression AddExpression(ClLinearExpression expr, double n, ClAbstractVariable subject, ClTableau solver)
{
IncrementConstant(n * expr.Constant);
foreach (ClAbstractVariable clv in expr.Terms.Keys)
{
double coeff = (expr.Terms[clv]).Value;
AddVariable(clv, coeff * n, subject, solver);
}
return(this);
}
/// <summary>
/// Replace var with a symbolic expression expr that is equal to it.
/// If a variable has been added to this expression that wasn't there
/// before, or if a variable has been dropped from this expression
/// because it now has a coefficient of 0, inform the solver.
/// PRECONDITIONS:
/// var occurs with a non-zero coefficient in this expression.
/// </summary>
public /*sealed*/ void SubstituteOut(ClAbstractVariable var, ClLinearExpression expr,
ClAbstractVariable subject, ClTableau solver)
{
if (Trace)
FnEnterPrint(string.Format("CLE:SubstituteOut: {0}, {1}, {2}, ...", var, expr, subject));
if (Trace)
TracePrint("this = " + this);
double multiplier = ((ClDouble) _terms[var]).Value;
_terms.Remove(var);
IncrementConstant(multiplier * expr.Constant);
foreach (ClAbstractVariable clv in expr.Terms.Keys)
{
double coeff = ((ClDouble) expr.Terms[clv]).Value;
ClDouble d_old_coeff = (ClDouble) _terms[clv];
if (d_old_coeff != null)
{
double old_coeff = d_old_coeff.Value;
double newCoeff = old_coeff + multiplier * coeff;
if (Cl.Approx(newCoeff, 0.0))
{
solver.NoteRemovedVariable(clv, subject);
_terms.Remove(clv);
}
else
{
d_old_coeff.Value = newCoeff;
}
}
else
{
// did not have that variable already
_terms.Add(clv, new ClDouble(multiplier * coeff));
solver.NoteAddedVariable(clv, subject);
}
}
if (Trace)
TracePrint("Now this is " + this);
}
/// <summary>
/// Add a term c*v to this expression. If the expression already
/// contains a term involving v, add c to the existing coefficient.
/// If the new coefficient is approximately 0, delete v. Notify the
/// solver if v appears or disappears from this expression.
/// </summary>
public /*sealed*/ ClLinearExpression AddVariable(ClAbstractVariable v, double c,
ClAbstractVariable subject, ClTableau solver)
{
// body largely duplicated above
if (Trace)
FnEnterPrint(string.Format("AddVariable: {0}, {1}, {2}, ...", v, c, subject));
ClDouble coeff = (ClDouble) _terms[v];
if (coeff != null)
{
double new_coefficient = coeff.Value + c;
if (Cl.Approx(new_coefficient, 0.0))
{
solver.NoteRemovedVariable(v, subject);
_terms.Remove(v);
}
else
{
coeff.Value = new_coefficient;
}
}
else
{
if (!Cl.Approx(c, 0.0))
{
_terms.Add(v, new ClDouble(c));
solver.NoteAddedVariable(v, subject);
}
}
return this;
}
/// <summary>
/// Add n*expr to this expression from another expression expr.
/// Notify the solver if a variable is added or deleted from this
/// expression.
/// </summary>
public /*sealed*/ ClLinearExpression AddExpression(ClLinearExpression expr, double n,
ClAbstractVariable subject, ClTableau solver)
{
IncrementConstant(n * expr.Constant);
foreach (ClAbstractVariable clv in expr.Terms.Keys)
{
double coeff = ((ClDouble) expr.Terms[clv]).Value;
AddVariable(clv, coeff * n, subject, solver);
}
return this;
}
