 
bool csdgather=y [y/n]  default, common shotgather; if n, record at every point

float fm=  dominant freq of ricker

int gxbeg=  xbegining index of receivers, starting from 0

int gzbeg=  zbegining index of receivers, starting from 0

file imag2=  auxiliary output file name

int jgx=1  receiver xaxis jump interval

int jgz=0  receiver zaxis jump interval

int jsx=  source xaxis jump interval

int jsz=0  source zaxis jump interval

int ng=  total receivers in each shot

int nt=  total modeling time steps

int order=6  order of finite difference, order=2,4,6,8,10

float phost=0  phost% points on host with zerocopy pinned memory, the rest on device

int sxbeg=  xbegining index of sources, starting from 0

int szbeg=  zbegining index of sources, starting from 0

int tdmute=2.0/(fm*dt)  number of deleyed time samples to mute

float vmute=1500  muting velocity to remove the lowfreq artifacts, unit=m/s

