void ImmersedBoundaryMethod::InterpolateFluidVelocity()
{
const auto nx = lm_.GetNumberOfColumns();
const auto ny = lm_.GetNumberOfRows();
const auto dx = lm_.GetSpaceStep();
const auto dt = lm_.GetTimeStep();
const auto scaling = dx / dt;
// pointer always editable, do not need &
for (auto particle : particles) {
for (auto &node : particle->nodes) {
node.u = {0.0, 0.0};
const auto x_particle = node.coord[0];
const auto y_particle = node.coord[1];
// fix for truncation error when double is really close to integer value
// http://blog.frama-c.com/index.php?post/2013/05/02/nearbyintf1
// uses "machine epsilon" through std::numeric_limits<double>::epsilon()
// http://stackoverflow.com/questions/17333/most-effective-way-for-float-
// and-double-comparison
const auto x_fluid = static_cast<int>(floor(x_particle + 2 *
particle->char_length * std::numeric_limits<double>::epsilon()));
const auto y_fluid = static_cast<int>(floor(y_particle + 2 *
particle->char_length * std::numeric_limits<double>::epsilon()));
for (auto y = y_fluid; y < y_fluid + 2; ++y) {
for (auto x = x_fluid; x < x_fluid + 2; ++x) {
const auto n = ((y + ny) % ny) * nx + (x + nx) % nx;
const auto weight = Dirac(stencil_, x_particle - x, y_particle - y);
// node velocity maybe calculated in dimensionless units (check)
node.u[0] += lm_.u[n][0] / scaling * weight;
node.u[1] += lm_.u[n][1] / scaling * weight;
} // x
} // y
} // node
} // particle
}
ImageF drlse_edge(ImageF phi_0,ImageF g,float lambda,float mu,float alfa,float epsilon,int timestep, int iter,string sada,char * potentialFunction)
{
ImageF phi=phi_0;
for(int i=0;i<iter;i++)
{
phi=NeumannBoundCond(phi);
ImageF *vx=new ImageF();
ImageF *vy=new ImageF();
(*vy)*(vx);
ImageF *phi_x=new ImageF();
ImageF *phi_y=new ImageF();
*vx=gradientx(g);
*vy=gradienty(g);
*phi_x=gradientx(g);
*phi_y=gradienty(g);
ImageF *s=new ImageF();
*s=ImageFSqrt( *vx, *vy);
float smallNumber=1e-10;
ImageF *Nx,*Ny;
*Nx=*phi_x/(*s+smallNumber);
*Ny=*phi_y/(*s+smallNumber);
ImageF * curvature=new ImageF();
*curvature=div(*Nx,*Ny);
ImageF distRegTerm;
if (strcmp(potentialFunction,"single-well"))
/*
compute distance regularization term in equation (13)
with the single-well potential p1.
*/
distRegTerm= 4*del2(phi)-*curvature;
//printf("");
else if (strcmp(potentialFunction,"double-well"))
{
distRegTerm=distReg_p2(phi); // compute the distance regularization term in eqaution (13) with the double-well potential p2.
printf("asda");
}
else printf("EEROR");
//float eplsion=0.1;
ImageF diracPhi=Dirac(phi,epsilon);
ImageF areaTerm=diracPhi*g;
ImageF *edgeTerm=new ImageF();
*edgeTerm=diracPhi*(*vx**Nx+*vy**Ny) + diracPhi*g*(*curvature);
//vx*vy;
phi=phi + timestep*(mu*distRegTerm + lambda**edgeTerm + alfa*areaTerm);
return phi_0;
}
}
void ImmersedBoundaryMethod::SpreadForce()
{
// The two-point interpolation stencil (bi-linear interpolation) is used in
// the present code.
fluid_force.assign(fluid_force.size(), {0.0, 0.0});
const auto nx = lm_.GetNumberOfColumns();
const auto ny = lm_.GetNumberOfRows();
const auto dx = lm_.GetSpaceStep();
const auto dt = lm_.GetTimeStep();
const auto scaling = dx / dt / dt;
for (auto particle : particles) {
for (auto &node : particle->nodes) {
// Identify the lowest fluid lattice node in interpolation range.
// The other fluid nodes in range have coordinates
// (x_fluid + 1, y_fluid), (x_fluid, y_fluid + 1), and
// (x_fluid + 1, y_fluid + 1).
const auto x_particle = node.coord[0];
const auto y_particle = node.coord[1];
const auto x_fluid = static_cast<int>(floor(x_particle + 2 *
particle->char_length * std::numeric_limits<double>::epsilon()));
const auto y_fluid = static_cast<int>(floor(y_particle + 2 *
particle->char_length * std::numeric_limits<double>::epsilon()));
std::cout << x_particle << " " << x_fluid << std::endl;
// Consider unrolling these 2 loops
for (auto y = y_fluid; y < y_fluid + 2; ++y) {
for (auto x = x_fluid; x < x_fluid + 2; ++x) {
const auto n = ((y + ny) % ny) * nx + (x + nx) % nx;
// Compute interpolation weights based on distance using interpolation
// stencil, still need to implement others
const auto weight = Dirac(stencil_, x_particle - x, y_particle - y);
// Compute fluid force
fluid_force[n][0] += node.force[0] * scaling * weight;
fluid_force[n][1] += node.force[1] * scaling * weight;
} // x
} // y
} // node
} // particle
}
void Evolution(IplImage *u, IplImage *g, double lambda, double mu, double alf, double epsilon, double delt, int numIter)
{
if (!u||!g)
return;
CvSize size = cvGetSize(u);
IplImage* vx = cvCreateImage(size,IPL_DEPTH_32F,1);
IplImage* vy = cvCreateImage(size,IPL_DEPTH_32F,1);
IplImage* ux = cvCreateImage(size,IPL_DEPTH_32F,1);
IplImage* uy = cvCreateImage(size,IPL_DEPTH_32F,1);
IplImage* Nx = cvCreateImage(size,IPL_DEPTH_32F,1);
IplImage* Ny = cvCreateImage(size,IPL_DEPTH_32F,1);
IplImage* diracU = cvCreateImage(size,IPL_DEPTH_32F,1);
IplImage* K = cvCreateImage(size,IPL_DEPTH_32F,1);
IplImage* laplace = cvCreateImage(size,IPL_DEPTH_32F,1);
Sobel(g, vx, vy);
int i,j;
CvScalar cur1,cur2,cur11,cur22,cur;
CvScalar Cdirac, Cvx, CNx, Cvy, CNy, Cg, CK, Claplace, Cu;
for (int k=0;k<numIter;k++)
{
cout<<k<<"……"<<endl;
NeumannBoundCond(u);
Sobel(u, ux, uy);
for (i=0; i<size.height; i++)
{
for(j=0; j<size.width; j++)
{
cur1 = cvGet2D(ux,i,j);
cur2 = cvGet2D(uy,i,j);
cur11.val[0] = cur1.val[0]/sqrt(cur1.val[0]*cur1.val[0] + cur2.val[0]*cur2.val[0] + 1e-10);
cur22.val[0] = cur2.val[0]/sqrt(cur1.val[0]*cur1.val[0] + cur2.val[0]*cur2.val[0] + 1e-10);
cvSet2D(Nx,i,j,cur11);
cvSet2D(Ny,i,j,cur22);
}
}
Dirac(u,diracU,epsilon);
CurvatureCentral2(Nx,Ny,K);
cvLaplace(u, laplace, 1);
for (i=0; i<size.height; i++)
{
for(j=0; j<size.width; j++)
{
Cdirac = cvGet2D(diracU,i,j);
Cvx = cvGet2D(vx,i,j);
CNx = cvGet2D(Nx,i,j);
Cvy = cvGet2D(vy,i,j);
CNy = cvGet2D(Ny,i,j);
Cg = cvGet2D(g,i,j);
CK = cvGet2D(K,i,j);
Claplace = cvGet2D(laplace,i,j);
Cu = cvGet2D(u,i,j);
cur.val[0] = lambda*Cdirac.val[0]*(Cvx.val[0]*CNx.val[0] + Cvy.val[0]*CNy.val[0] + Cg.val[0]*CK.val[0])
+ mu*(Claplace.val[0]-CK.val[0]) + alf*Cdirac.val[0]*Cg.val[0];
Cu.val[0] += delt*cur.val[0];
cvSet2D(u,i,j,Cu);
}
}
}
cvReleaseImage(&vx);
cvReleaseImage(&vy);
cvReleaseImage(&ux);
cvReleaseImage(&uy);
cvReleaseImage(&Nx);
cvReleaseImage(&Ny);
cvReleaseImage(&diracU);
cvReleaseImage(&K);
cvReleaseImage(&laplace);
}
void Evolution2(IplImage * u, IplImage *g, double lambda, double mu, double alf, double epsilon, double delt, int numIter)
{
if (!u||!g)
return;
CvSize size = cvGetSize(u);
IplImage* vx = cvCreateImage(size,IPL_DEPTH_32F,1);
IplImage* vy = cvCreateImage(size,IPL_DEPTH_32F,1);
IplImage* ux = cvCreateImage(size,IPL_DEPTH_32F,1);
IplImage* uy = cvCreateImage(size,IPL_DEPTH_32F,1);
IplImage* Nx = cvCreateImage(size,IPL_DEPTH_32F,1);
IplImage* Ny = cvCreateImage(size,IPL_DEPTH_32F,1);
IplImage* diracU = cvCreateImage(size,IPL_DEPTH_32F,1);
IplImage* K = cvCreateImage(size,IPL_DEPTH_32F,1);
IplImage* Laplace = cvCreateImage(size,IPL_DEPTH_32F,1);
Sobel(g,vx,vy);
CvScalar s1,s2,s11,s22;
CvScalar Cdirac, Cvx, Cvy, CNx, CNy, Cg, CK, CLaplace, Cu;
int i,j;
for(int k=0;k<numIter;k++)
{
cout<<k<<"……"<<endl;
NeumannBoundCond(u);
Sobel(u,ux,uy);
for(i=0;i<size.height;i++)
{
for(j=0;j<size.width;j++)
{
s1=cvGet2D(ux,i,j);
s2=cvGet2D(uy,i,j);
double normDu=sqrt(pow(s1.val[0],2)+pow(s2.val[0],2)+1e-10);
s11.val[0]=s1.val[0]/normDu;
s22.val[0]=s2.val[0]/normDu;
cvSet2D(Nx,i,j,s11);
cvSet2D(Ny,i,j,s22);
}
}
Dirac(u,diracU,epsilon);
CurvatureCentral2(Nx,Ny,K);
cvLaplace(u, Laplace, 1);
for(i=0;i<size.height;i++)
{
for(j=0;j<size.width;j++)
{
Cdirac=cvGet2D(diracU,i,j);
Cvx=cvGet2D(vx,i,j);
Cvy=cvGet2D(vy,i,j);
CNx=cvGet2D(Nx,i,j);
CNy=cvGet2D(Ny,i,j);
Cg=cvGet2D(g,i,j);
CK=cvGet2D(K,i,j);
CLaplace=cvGet2D(Laplace,i,j);
Cu=cvGet2D(u,i,j);
double weightedLengthTerm=lambda*Cdirac.val[0]*(Cvx.val[0]*CNx.val[0]+Cvy.val[0]*CNy.val[0]+Cg.val[0]*CK.val[0]);
double weightedAreaTerm=alf*Cdirac.val[0]*Cg.val[0];
double penalizingTerm=mu*(CLaplace.val[0]-CK.val[0]);
double total=weightedLengthTerm+weightedAreaTerm+penalizingTerm;
Cu.val[0]+=delt*total;
cvSet2D(u,i,j,Cu);
}
}
}
cvReleaseImage(&vx);
cvReleaseImage(&vy);
cvReleaseImage(&ux);
cvReleaseImage(&uy);
cvReleaseImage(&Nx);
cvReleaseImage(&Ny);
cvReleaseImage(&diracU);
cvReleaseImage(&K);
cvReleaseImage(&Laplace);
}
