eikonal_traveltime Computes traveltime between sources and receivers by solving the eikonal equation
 
  t=eikonal_traveltime(x,y,z,V,Sources,Receivers,iuse,type);
 
   x,y,z : arrays defining the x, y, and z axis
   V: velocity field, with size (length(y),length(x),length(z));
   Sources [ndata,ndim] : Source positions
   Receivers [ndata,ndim] : Receiver positions
   iuse (optional): optionally only use subset of data. eg.g i_use=[1 2 4];
   type (optional): type of eikonal solver: [1]:Fast Marching(default), [2]:FD
 
   tmap [size(V)]: travel times computed everywhere in the velocity grid
 
 %Example (2%
 
  Example 2d traveltime compuation
 
  Example (2D):
    x=[1:1:100];
    y=1:1:100;
    z=1;
    V=ones(100,100);V(:,1:50)=2;
    S=[50 50 1;50 50 1];
    R=[90 90 1; 90 80 1];
    t=eikonal_traveltime(x,y,z,V,S,R)
 
  Example (3D):
    nx=50;ny=50;nz=50;
    x=1:1:nx;
    y=1:1:ny;
    z=1:1:nz;
    V=ones(ny,nx,nz);V(:,1:50,:)=2;
    S=[10 10 1;10 10 1;10 9 1];
    R=[40 40 40; 40 39 40; 40 40 40];
    t=eikonal_traveltime(x,y,z,V,S,R)
 
 
  See also eikonal