%read a file and plot
function draw2D(F,N)
fid=fopen(F,'r'); 
A=fscanf(fid,'%e',[N,inf]);
fclose(fid);

%clear;
%N=14;
%A=rand(N,100);
A=A.';

ik=1;
for id=1:2:N
    Ax(:,ik)=A(:,id);
    Ay(:,ik)=A(:,id+1);
    ik=ik+1;
end

h1=plot(Ax,Ay);
set(h1,'linewidth',2);
