 axial diffusion tensor, corresponding to <code>[txy txy tz]</code>
<li>3 numbers <code>[tx ty tz]</code>: anisotropic diffusion with rhombic diffusion tensor
</ul>

<p>For example,
<pre class="matlab">
Sys.tcorr = 1e-9;         % isotropic diffusion, 1 ns correlation time
Sys.tcorr = [5 1]*1e-9;   % axial anisotropic diffusion, 5 ns around x and y axes, 1 ns around z
Sys.tcorr = [5 4 1]*1e-9; % rhombic anisotropic diffusion
</pre>
  
<p>
Instead of <code>tcorr</code>, <code>Diff</code> can be used, see bel