Q_prior[:, sample] = eqn.q[:]
                sample += 1
        except:
            pass
    
    dirname ="solution"
    y, u, R11, R12, R22, R33, omega = load_solution_stressomega(dirname)
    eqn = StressOmegaEquation(y, u, R11, R12, R22, R33, omega, Retau)
    eqn.beta[:] = np.loadtxt("inverse_solution/beta.%i"%maxiter)
    eqn.writedir = "/tmp"
    # first dt can be large as we restart from a good solution
    eqn.force_boundary = False
    eqn.dt = 1e1
    eqn.tol = tol
    eqn.solve()
    eqn.postprocess(eqn.q)
    eqn_map = copy.deepcopy(eqn)
    up_map = eqn.up.copy()

    qtarget = np.zeros_like(eqn.q)
    dns, wilcox, wilcox_kw = load_data()

    utau = Retau*eqn.nu*2.0
    ydns = dns.y*0.5
    ub = dns.u*utau
    R11b = -(dns.ub*utau)**2
    R22b = -(dns.vb*utau)**2
    R33b = -(dns.wb*utau)**2
    R12b = -dns.uv*utau*utau
    
    f = interp1d(ydns, ub)