legend({'$\epsilon_{\mathrm{rel}}^{\Omega}$ using cg','$\epsilon_{\mathrm{rel}}$ using cg','$\epsilon_{\mathrm{rel}}^{\Omega}$ using FISTA','$\epsilon_{\mathrm{rel}}$ using FISTA'},'Interpreter','latex','Location','southeast')
legend({'$\epsilon_{\mathrm{rel}}^{\Omega}$ using cg','$\epsilon_{\mathrm{rel}}$ using cg','$\epsilon_{\mathrm{rel}}^{\Omega}$ using FISTA','$\epsilon_{\mathrm{rel}}$ using FISTA'},'Interpreter','latex','Location','southeast')