// scale gradients for the whole one pyramid with the use of (Cx,Cy) from the other pyramid
static void pyramid_scale_gradient(pyramid_t* pyramid, pyramid_t* pC)
{
while (pyramid != NULL)
{
const int size = pyramid->rows * pyramid->cols;
scale_gradient(size, pyramid->Gx, pC->Gx);
scale_gradient(size, pyramid->Gy, pC->Gy);
pyramid = pyramid->next;
pC = pC->next;
}
}
int main(int argc, char *argv[]) {
/* initialize Madagascar */
sf_init(argc, argv);
Logger::instance().init("serial-fwi");
FwiParams ¶ms = FwiParams::instance();
std::vector<float> dobs(params.ns * params.nt * params.ng); /* observed data */
std::vector<float> cg(params.nz * params.nx, 0); /* conjugate gradient */
std::vector<float> g0(params.nz * params.nx, 0); /* gradient at previous step */
std::vector<float> wlt(params.nt); /* ricker wavelet */
std::vector<float> objval(params.niter, 0); /* objective/misfit function */
/* initialize wavelet */
rickerWavelet(&wlt[0], params.nt, params.fm, params.dt, params.amp);
ShotPosition allSrcPos(params.szbeg, params.sxbeg, params.jsz, params.jsx, params.ns, params.nz);
ShotPosition allGeoPos(params.gzbeg, params.gxbeg, params.jgz, params.jgx, params.ng, params.nz);
// read velocity
Velocity v0 = SfVelocityReader::read(params.vinit, params.nx, params.nz);
// read observed data
ShotDataReader::serialRead(params.shots, &dobs[0], params.ns, params.nt, params.ng);
EnquistAbc2d fmMethod(params.dt, params.dx, params.dz);
Velocity vel = fmMethod.expandDomain(v0);
float obj0 = 0;
for (int iter = 0; iter < params.niter; iter++) {
boost::timer::cpu_timer timer;
std::vector<float> g1(params.nz * params.nx, 0); /* gradient at curret step */
std::vector<float> derr(params.ns * params.ng * params.nt, 0); /* residual/error between synthetic and observation */
std::vector<float> illum(params.nz * params.nx, 0); /* illumination of the source wavefield */
Velocity vtmp = vel; /* temporary velocity computed with epsil */
fmMethod.bindVelocity(vel);
/**
* calculate local objective function & derr & illum & g1(gradient)
*/
float obj = cal_obj_derr_illum_grad(params, &derr[0], &illum[0], &g1[0], &wlt[0], &dobs[0], fmMethod, allSrcPos, allGeoPos);
DEBUG() << format("sum_derr %f, sum_illum %f, sum_g1 %f") % sum(derr) % sum(illum) % sum(g1);
objval[iter] = iter == 0 ? obj0 = obj, 1.0 : obj / obj0;
float epsil = 0;
float beta = 0;
sf_floatwrite(&illum[0], params.nz * params.nx, params.illums);
scale_gradient(&g1[0], &vel.dat[0], &illum[0], params.nz, params.nx, params.precon);
bell_smoothz(&g1[0], &illum[0], params.rbell, params.nz, params.nx);
bell_smoothx(&illum[0], &g1[0], params.rbell, params.nz, params.nx);
sf_floatwrite(&g1[0], params.nz * params.nx, params.grads);
DEBUG() << format("before beta: sum_g0: %f, sum_g1: %f, sum_cg: %f") % sum(g0) % sum(g1) % sum(cg);
beta = iter == 0 ? 0.0 : cal_beta(&g0[0], &g1[0], &cg[0], params.nz, params.nx);
cal_conjgrad(&g1[0], &cg[0], beta, params.nz, params.nx);
epsil = cal_epsilon(&vel.dat[0], &cg[0], params.nz, params.nx);
cal_vtmp(&vtmp.dat[0], &vel.dat[0], &cg[0], epsil, params.nz, params.nx);
std::swap(g1, g0); // let g0 be the previous gradient
fmMethod.bindVelocity(vtmp);
float alpha = calVelUpdateStepLen(params, &wlt[0], &dobs[0], &derr[0], epsil, fmMethod, allSrcPos, allGeoPos);
update_vel(&vel.dat[0], &cg[0], alpha, params.nz, params.nx);
sf_floatwrite(&vel.dat[0], params.nz * params.nx, params.vupdates);
// output important information at each FWI iteration
INFO() << format("iteration %d obj=%f beta=%f epsil=%f alpha=%f") % (iter + 1) % obj % beta % epsil % alpha;
// INFO() << timer.format(2);
} /// end of iteration
sf_floatwrite(&objval[0], params.niter, params.objs);
sf_close();
return 0;
}
