1;
function dostuff()
  i = 0;
  col = ["r","g","b","k","5","6","y"];
  mass = 20*(1.66e-27);

  var2 = load("Velpertd.txt");

  j=figure(1)#,"visible","off");
  plot(var2(:,1)+27,var2(:,3)/1e6,"-m","linewidth",3);
  hold;
  x = 1;
  for  i = 2:1:8;
    filname = strcat(num2str(i),"pi__10.dat");
    var = load(filname);
    type = strcat("-",col(x));
    plot(var(:,1)*1e6,(var(:,2)/mass)/1e6,type,"linewidth",3);
    x=x+1;
  endfor

  xlabel("x position in microns");
  ylabel("Velocity (10^{6}ms^{-1})");
  tit = strcat("Ion velocity perturbation at t = 100fs for varying ionisations");
  title(tit);
  axis([25,35,0,1]);
  grid('on');
  set(gca(),'xtick',25:0.5:35);
  set(gca(),'ytick',0:0.1:1);
  h =  legend("Perturbation Used","2","3","4","5","6","7","8");
  legend location northeast;
  #outfilnam=strcat("");
  hold
  saveas(j,"AApxim100.png","png")
endfunction
dostuff()
