// initialize exact solution
void setExactSolution(FVMesh2D &m,FVVect<double> &sol,Parameter ¶) {
FVCell2D *ptr_c;
m.beginCell();
while((ptr_c=m.nextCell())) {
sol[ptr_c->label-1]=ptr_c->getMeanValue(solExact,para);
}
}
// compute source term
void setRHS(FVMesh2D &m,FVVect<double> &rhs,Parameter ¶) {
FVCell2D *ptr_c;
m.beginCell();
while((ptr_c=m.nextCell())) {
rhs[ptr_c->label-1]=ptr_c->getMeanValue(RHS,para);
}
}
void Gmsh::FVMesh2Gmsh(FVMesh2D &m) // constructor which convert a FVMesh2D into a gmah struct
{
_dim=2; // a two dimension mesh
FVVertex2D* ptr_v;
_nb_node=m.getNbVertex();
_node.resize(_nb_node);
for((ptr_v=m.beginVertex()); (ptr_v=m.nextVertex());)
{
size_t i=ptr_v->label;
_node[i-1].label = i;
_node[i-1].coord.x= ptr_v->coord.x;
_node[i-1].coord.y= ptr_v->coord.y;
_node[i-1].coord.z= 0;
}
FVCell2D *ptr_c;
double order[4],doux;
size_t noux;
FVPoint2D<double> Paux;
_nb_element=m.getNbCell();
_element.resize(_nb_element);
for((ptr_c=m.beginCell()); (ptr_c=m.nextCell());)
{
size_t i=ptr_c->label;
_element[i-1].label=i;
switch(ptr_c->nb_vertex)
{
case 3:
_element[i-1].type_element=2; // we use triangle
break;
case 4:
_element[i-1].type_element=3; // we use quadrangle
break;
default:
cout<<"cell does not correspond to a gmsh element. Abort convertion"<<endl;
_nb_node=0;
_nb_element=0;
return;
}
_element[i-1].code_physical=ptr_c->code;
_element[i-1].code_elementary=ptr_c->code;
_element[i-1].dim=_dim;
_element[i-1].nb_node=ptr_c->nb_vertex;
for(size_t j=0; j<ptr_c->nb_vertex; j++)
{
_element[i-1].node[j]=ptr_c->vertex[j]->label;
Paux.x=_node[_element[i-1].node[j]-1].coord.x-ptr_c->centroid.x;
Paux.y=_node[_element[i-1].node[j]-1].coord.y-ptr_c->centroid.y;
Paux/=Norm(Paux);
order[j]=(1-Paux.x)*0.5;
if(Paux.y<0) order[j]*=-1;
}
// reordering the node (bubble sort) to cast in the gmah framework following order
for(size_t j=ptr_c->nb_vertex-1; j>0; j--)
{
for(size_t k=0; k<j; k++)
{
if(order[k+1]<order[k])
{
doux=order[k+1];
noux=_element[i-1].node[k+1];
order[k+1]=order[k];
_element[i-1].node[k+1]=_element[i-1].node[k];
order[k]=doux;
_element[i-1].node[k]=noux;
}
}
}
}
}
