public void setStep(double dt)
{
dt_ = dt;
implicitPart_ = (Operator)L_.add(I_, L_.multiply(0.5 * alpha_ * dt_, L_));
explicitTrapezoidalPart_ = (Operator)L_.subtract(I_, L_.multiply(0.5 * alpha_ * dt_, L_));
explicitBDF2PartFull_ = (Operator)I_.multiply(-(1.0 - alpha_) * (1.0 - alpha_) / (alpha_ * (2.0 - alpha_)), I_);
explicitBDF2PartMid_ = (Operator)I_.multiply(1.0 / (alpha_ * (2.0 - alpha_)), I_);
}
void translate(object pc_s, object pc_t)
{
trans:
// put (pc_s, pc_t) in codemap if not already there
// get instruction from pc_s
var I = GetNextInstr();
RtlInstruction I_;
switch (I.Class())
{
case Class.NCT:
emit(I.Rtl);
goto trans;
case Class.SU:
emit(goto I.nPC);
queueForTranslation(I.nPC);
case Class.SD:
case Class.DD:
// get next instruction.
I_ = GetNextInstr();
switch (I_.Class())
{
case Class.NCT:
emit(I.I_c);
emit(I_.I_c);
emitGoto(I.nPc);
queueForTranslation(I.nPC);
}
case Class.SCD:
I_ = GetNextInstr();
switch (I_.Class())
{
case Class.NCT:
var bb = newBlock();
emit(I_.I_c);
emit("if I.b goto bb");
// switch to bb.
emit(I_.I_c);
emitGoto(I.nPC);
goto trans;
}
}
}
public void step(ref object a, double t, double theta = 1.0)
{
int i;
Vector aInit = new Vector((a as Vector).size());
for (i = 0; i < (a as Vector).size(); i++)
{
aInit[i] = (a as Vector)[i];
}
aInit_ = aInit;
for (i = 0; i < bcs_.Count; i++)
{
bcs_[i].setTime(t);
}
//trapezoidal explicit part
if (L_.isTimeDependent())
{
L_.setTime(t);
explicitTrapezoidalPart_ = (Operator)I_.subtract(I_, L_.multiply(-0.5 * alpha_ * dt_, L_));
}
for (i = 0; i < bcs_.Count; i++)
{
bcs_[i].applyBeforeApplying(explicitTrapezoidalPart_);
}
a = explicitTrapezoidalPart_.applyTo((a as Vector));
for (i = 0; i < bcs_.Count; i++)
{
bcs_[i].applyAfterApplying((a as Vector));
}
// trapezoidal implicit part
if (L_.isTimeDependent())
{
L_.setTime(t - dt_);
implicitPart_ = (Operator)I_.add(I_, L_.multiply(0.5 * alpha_ * dt_, L_));
}
for (i = 0; i < bcs_.Count; i++)
{
bcs_[i].applyBeforeSolving(implicitPart_, (a as Vector));
}
a = implicitPart_.solveFor((a as Vector));
for (i = 0; i < bcs_.Count; i++)
{
bcs_[i].applyAfterSolving((a as Vector));
}
// BDF2 explicit part
if (L_.isTimeDependent())
{
L_.setTime(t);
}
for (i = 0; i < bcs_.Count; i++)
{
bcs_[i].applyBeforeApplying(explicitBDF2PartFull_);
}
Vector b0 = explicitBDF2PartFull_.applyTo(aInit_);
for (i = 0; i < bcs_.Count; i++)
{
bcs_[i].applyAfterApplying(b0);
}
for (i = 0; i < bcs_.Count; i++)
{
bcs_[i].applyBeforeApplying(explicitBDF2PartMid_);
}
Vector b1 = explicitBDF2PartMid_.applyTo((a as Vector));
for (i = 0; i < bcs_.Count; i++)
{
bcs_[i].applyAfterApplying(b1);
}
a = b0 + b1;
// reuse implicit part - works only for alpha=2-sqrt(2)
for (i = 0; i < bcs_.Count; i++)
{
bcs_[i].applyBeforeSolving(implicitPart_, (a as Vector));
}
a = implicitPart_.solveFor((a as Vector));
for (i = 0; i < bcs_.Count; i++)
{
bcs_[i].applyAfterSolving((a as Vector));
}
}