[SIESTA-L] how to deal with fermi energy when I plot the density of states

[shihitwh]

Dear siesta users,
I have calculated the DOS file, I plot the density of states with Origin.When I 
plot the density of states, I get a problem. How can I plot "Energy relative to 
the Fermi energy"? I means how  I can add the Fermi energy to the density of 
states. 
Best Wishes!
Shi