x_to_norm.m

 function [x_norm] = x_to_norm_v2(x_begin,x_end)
 
 if nargin ~= 2
      error('Wrong number of input arguments.')
 end
 
 h_axes = get(gcf,'CurrentAxes');    %get axes handle
 
 axesoffsets = get(h_axes,'Position');
 x_axislimits = get(gca, 'xlim');     %get axes extremeties.
 x_dir = get(gca,'xdir');
 x_scale = get(gca,'xscale');
 
 %get axes length
 x_axislength_lin = abs(x_axislimits(2) - x_axislimits(1));
 
 
 if strcmp(x_dir,'normal')
   if strcmp(x_scale,'log')
     x_axislength_log = abs(log10(x_axislimits(2)) - log10(x_axislimits(1)));  
     x_begin_norm = axesoffsets(1)+axesoffsets(3)*abs(log10(x_begin)-log10(x_axislimits(1)))/(x_axislength_log);
     x_end_norm = axesoffsets(1)+axesoffsets(3)*abs(log10(x_end)-log10(x_axislimits(1)))/(x_axislength_log);
 
     x_norm = [x_begin_norm x_end_norm];
   elseif strcmp(x_scale,'linear')
     x_begin_norm = axesoffsets(1)+axesoffsets(3)*abs((x_begin-x_axislimits(1))/x_axislength_lin);
     x_end_norm = axesoffsets(1)+axesoffsets(3)*abs((x_end-x_axislimits(1))/x_axislength_lin);
 
     x_norm = [x_begin_norm x_end_norm];  
   else
       error('use only lin or log in quotes for scale')
   end   
    
 elseif strcmp(x_dir,'reverse')
     if strcmp(x_scale,'log')
         x_axislength_log = abs(log10(x_axislimits(2)) - log10(x_axislimits(1)));
         x_begin_norm = axesoffsets(1)+axesoffsets(3)*abs(log10(x_axislimits(2))-log10(x_begin))/(x_axislength_log);
         x_end_norm = axesoffsets(1)+axesoffsets(3)*abs(log10(x_axislimits(2))-log10(x_end))/(x_axislength_log);
 
         x_norm = [x_begin_norm x_end_norm]; 
     elseif strcmp(x_scale,'linear')
         x_begin_norm = axesoffsets(1)+axesoffsets(3)*abs((x_axislimits(2)-x_begin)/x_axislength_lin);
         x_end_norm = axesoffsets(1)+axesoffsets(3)*abs((x_axislimits(2)-x_end)/x_axislength_lin);
 
         x_norm = [x_begin_norm x_end_norm];
     else
         error('use only lin or log in quotes for scale')
     end
 else
     error('use only r or nr in quotes for reverse')
 end