use the shift-inverse method for finding sparse eigenvalues in tutorial

a334de16 · Bas Nijholt · Joseph Weston · 4076779d · a334de16
Commit a334de16 authored 6 years ago by Bas Nijholt Committed by Joseph Weston 6 years ago
--- a/doc/source/code/figure/closed_system.py.diff
+++ b/doc/source/code/figure/closed_system.py.diff
@@ -71,7 +71,7 @@
         ham_mat = syst.hamiltonian_submatrix(args=[B], sparse=True)
 
         # we only calculate the 15 lowest eigenvalues
-         ev = sla.eigsh(ham_mat, k=15, which='SM', return_eigenvectors=False)
+         ev = sla.eigsh(ham_mat, k=15, sigma=0, return_eigenvectors=False)
 
         energies.append(ev)