Magnetic equations with FreeFem++: The Grad-Shafranov equation & the current hole Erwan Deriaz, Bruno Despres, Gloria Faccanoni, Kirill Pichon Gostaf, Lise-Marie Imbert-Gérard, Georges Sadaka and Remy Sart ESAIM: Proc., 32 (2011) 76-94 Published online: 03 November 2011 DOI: 10.1051/proc/2011013