void CreateMap() { //Our 'main' function
int x,y,color; //Holds the result of slove
for(y=0;y<HEIGHT;y++) //Main loop for map generation
for(x=0;x<WIDTH;x++){
color=solve(translate_x(x),translate_y(y))*colorcount/100;
#ifdef GRAPHICS
gs_plot(x,y,colortable[color]); //Plot the coordinate to map
#else
crc+=colortable[color];
#endif
}
#ifdef GRAPHICS
gs_update();
#endif
}
int main(int argc, char* argv[])
{
int nz,nx,na;
float oz,ox,oa;
float dz,dx,da;
int iq; /* escape variables switch */
int ix; /* grid points in x */
int iz; /* grid points in z */
int ia; /* grid points in a */
int iter, niter; /* number of iterations */
int ix0, ix1, ixs;
int iz0, iz1, izs;
int ia0, ia1, ias;
float a; /* angle */
float ***t; /* escape variable */
float **v,**vx,**vz; /* slowness, gradients */
float vel, velx, velz;
float cs,sn;
float new_val;
float cvt,tol;
sf_file in,out,slow,slowz,slowx;
float sl_vti, sl_vti_inv;
char is_P_SH_SV, *whatV;
float Hp, Hq, p_gradH, dl_dsigma, da_dsigma;
float
vti_eps = 0.20, /*0.2, */
vti_gamma=0.20, /*0.2, */
vti_delta=-0.450; /*-0.45;*/
struct VTIStruct VTI;
/* bool swap_dir_x=1, swap_dir_z=1; */
sf_init(argc,argv);
in = sf_input("in");
out = sf_output("out");
if (!sf_getint("iq",&iq)) sf_error("Need iq=");
/* switch for escape variable 0=x, 1=a, 2=t, 3=z, 4=l */
whatV = sf_getstring ("vti");
/* what to compute (p=qP, v=qSV, h=SH) */
if (NULL == whatV) {
whatV = "p";
} else {
if (whatV[0] != 'p' && whatV[0] != 'v' && whatV[0] != 'h')
sf_error ("Need vti=p|v|h");
}
is_P_SH_SV = whatV[0];
/* read input file parameters */
if (SF_FLOAT != sf_gettype(in)) sf_error("Need float");
if (!sf_histint(in,"n1",&nz)) sf_error("No n1=");
if (!sf_histfloat(in,"d1",&dz)) sf_error("No d1=");
if (!sf_histfloat(in,"o1",&oz)) sf_error("No o1=");
if (!sf_histint(in,"n2",&nx)) sf_error("No n2=");
if (!sf_histfloat(in,"d2",&dx)) sf_error("No d2=");
if (!sf_histfloat(in,"o2",&ox)) sf_error("No o2=");
if (!sf_histint(in,"n3",&na)) sf_error("No n3=");
if (!sf_histfloat(in,"d3",&da)) sf_error("No d3=");
if (!sf_histfloat(in,"o3",&oa)) sf_error("No o3=");
/* angle in degrees */
if (!sf_getint("niter",&niter)) niter=50;
/* number of Gauss-Seidel iterations */
if (!sf_getfloat("tol",&tol)) tol=0.000002*nx*nz;
/* accuracy tolerance */
if (!sf_getfloat("vti_eps",&vti_eps)) vti_eps=0.0;
if (!sf_getfloat("vti_gamma",&vti_gamma)) vti_gamma=0.0;
if (!sf_getfloat("vti_delta",&vti_delta)) vti_delta=0.0;
/* VTI constants Thomsen */
/* memory allocations */
/* Solution vector */
t = sf_floatalloc3(nz,nx,na);
/* read input escape variable - initial guess */
sf_floatread(t[0][0],nz*nx*na,in);
/*
for (int ix=0; ix < nx; ix++)
for (int iz=0; iz < nz; iz++)
for (int ia=0; ia < na; ia++)
t[ia][ix][iz] = 1e10f;
*/
/* read auxiliary slowness file */
slow = sf_input("vel");
v = sf_floatalloc2(nz,nx);
sf_floatread(v[0],nz*nx,slow);
/* read auxiliary slowness z-gradient file */
slowz = sf_input("velz");
vz = sf_floatalloc2(nz,nx);
sf_floatread(vz[0],nz*nx,slowz);
/* read auxiliary slowness x-gradient file */
slowx = sf_input("velx");
vx = sf_floatalloc2(nz,nx);
sf_floatread(vx[0],nz*nx,slowx);
/* convert to radians */
oa *= SF_PI/180.;
da *= SF_PI/180.;
ia0=0; ia1=na; ias=1;
gsray_init(nz,nx,na,
oz,ox,oa,
dz,dx,da);
/* Greenriver shale example
alfa=3.29 beta=1.77 eps=0.195 gamma=0.18 delat=-0.45 */
vti_init_greenriver_c(&VTI);
vti_c2thomsen(&VTI);
for (iter=0; iter < niter; iter++) {
cvt = 0.0; /* X_next - X_prev */
int num_fails = 0;
/* Gauss-Seidel iteration on angle */
for (ia = ia0; ia != ia1; ia += ias) {
a = oa + ia*da;
cs = cosf(a);
sn = sinf(a);
/* assert (fabs(sn) > 1e-6 && fabs(cs) > 1e-6);
Hq = -sn;
Hp = -cs; */
vti_gauss_2_c(&VTI, v[0][0], vx[0][0], vz[0][0], vti_eps, vti_gamma, vti_delta);
vti_c11_2_c1(&VTI);
sl_vti = vti_slowness_c(&VTI, cs*cs, sn*sn, is_P_SH_SV, &sl_vti_inv);
Svti(&VTI, sl_vti, sl_vti_inv, is_P_SH_SV, cs, sn, &Hp, &Hq, (float*)0, (float*)0, (float*)0);//&da_dsigma);
if (1e-6 < Hq) {
ix0=nx-2; ix1=-1; ixs=-1;
for (iz = 0; iz < nz; iz++)
boundary_mat(t,iz,nx-1,ia,iq);
} else {
ix0=1; ix1=nx; ixs=1;
for (iz = 0; iz < nz; iz++)
boundary_mat(t,iz,0,ia,iq);
}
if (1e-6 < Hp) {
iz0=nz-2; iz1=-1; izs=-1;
for (ix = 0; ix < nx; ix++)
boundary_mat(t,nz-1,ix,ia,iq);
} else {
iz0=1; iz1=nz; izs=1;
for (ix = 0; ix < nx; ix++)
boundary_mat(t,0,ix,ia,iq);
}
/* loop over grid Z.X */
for (ix = ix0; ix != ix1; ix += ixs) {
for (iz = iz0; iz != iz1; iz += izs) {
vel = v[ix][iz];
velx = vx[ix][iz];
velz = vz[ix][iz];
vti_gauss_2_c(&VTI, vel, velx, velz, vti_eps, vti_gamma, vti_delta);
vti_c11_2_c1(&VTI);
sl_vti = vti_slowness_c(&VTI, cs*cs, sn*sn, is_P_SH_SV, &sl_vti_inv);
Svti(&VTI, sl_vti, sl_vti_inv, is_P_SH_SV, cs, sn, &Hp, &Hq, &p_gradH, &dl_dsigma, &da_dsigma);
vti_c2thomsen(&VTI);
assert(fabs(VTI.eps - vti_eps) < 1e-6);
assert(fabs(VTI.gamma - vti_gamma) < 1e-6);
assert(fabs(VTI.delta - vti_delta) < 1e-6);
/* Gauss-Seidel update
new_val = gs_update(t,iz,ix,ia,ss,ssz,ssx,cs,sn,iq); */
new_val = gs_update(t,-Hp, -Hq, -da_dsigma, iz,ix,ia, p_gradH, dl_dsigma, iq);
/* new_val = fmin(new_val, t[ia][ix][iz]); */
cvt += fabsf(t[ia][ix][iz]-new_val);
/* t[ia][ix][iz] = fmin(new_val, t[ia][ix][iz]); */
t[ia][ix][iz] = new_val;
/* if (t[ia][ix][iz] > 1000) num_fails++; */
} /* ix */
} /* iz */
} /* ia */
sf_warning("Iter = %d, Norm L1 = %g num fails = %d sweep=%g %g",iter,cvt/(nx*nz*na), num_fails,Hp,Hq);
/* tol is tolerance for convergence */
if (cvt < tol) break;
/* alternate updating direction on angle grid*/
if (0 == ia0) {
ia0 = na-1; ia1 = -1; ias = -1;
} else {
ia0 = 0; ia1 = na; ias = 1;
}
} /* end G-S iterations */
/* output */
sf_floatwrite(t[0][0],nz*nx*na,out);
exit(0);
}
