function [x,y,z,T,stepanz]=bewegungsrichtung(u,s);
%**************************************************************************
% CLUSTER project: Cluster Flight                  Autor: Christian Maszl * 
% Unit System = [SI]                  Mail: e0025754@student.tuwien.ac.at *
%**************************************************************************
%
% This subroutine calculate the the path of the midpoint between
% satellite S1 and S3.

disp('Please choose the motion type: ');
disp('[a] In the current sheet (along y)');
disp('[b] Outside the current sheet (along y)');
disp('[c] Penetrate the current sheet (along x)');
howtomove=input('Please choose [a],[b] or [c]: ','s');
stepanz=input('How many time steps do you wish?: ');
% Use T as time base
T=(1:0.1:stepanz+1)';
%[a] In the current sheet (along y)
if (howtomove=='a')
   x(1:(10*stepanz)+1,1)=0;
   z(1:(10*stepanz)+1,1)=0;
   if (s>=u)
     disp('Warning: At least one statellite outside the current sheet!');
   end
   y=(-stepanz/2:0.1:stepanz/2)';
%[b] Outside the current sheet (along y)
elseif (howtomove=='b')
   z(1:(10*stepanz)+1,1)=0;
   y=(-stepanz/2:0.1:stepanz/2)';
   x=input('Distance to the x-axis [m]: x=');
   if (x<=u+s)
     disp('Warning: At least one satellite inside the current sheet');
   end
   x(1:(10*stepanz)+1,1)=x;
%[c] Penetrate the current sheet (along x)
elseif (howtomove=='c')
   y(1:(10*stepanz)+1,1)=0;
   z(1:(10*stepanz)+1,1)=0;
   x=(-stepanz/2:0.1:stepanz/2)';
else
end
