Eigen solver syntax in dolfin-x

16

I changed this. but every mode eigenvector is giving white colour contour only.
the code is

import dolfinx.io

with dolfinx.io.XDMFFile(MPI.COMM_WORLD, "eigenvector.xdmf", "w") as xdmf:
    xdmf.write_mesh(mesh)
eig_v=[]
ef = 0
print("Number of converged eigenpairs %d" % evs)
if evs > 0:

    for i in range(evs):
        e_val = eigensolver.getEigenpair(i, vr, vi)

        if (~np.isclose(e_val.real, 1.0)):
            # Calculation of eigenfrequency from real part of eigenvalue
            freq_3D = np.sqrt(e_val.real)/2/np.pi

            # Beam eigenfrequency
            if ef % 2 == 0:
                # exact solution should correspond to weak axis bending
                I_bend = H*B**3/12.
            else:
                # exact solution should correspond to strong axis bending
                I_bend = B*H**3/12.

            freq_beam = alpha(ef/2)**2*np.sqrt(E*I_bend/(rho*B*H*L**4))/2/np.pi

            print(
                "Solid FE: {0:8.5f} [Hz] "
                "Beam theory: {1:8.5f} [Hz]".format(freq_3D, freq_beam))
            

                
            ur = dolfinx.fem.Function(V)
            ur.vector.array[:] = vr
            xdmf.write_function(ur.copy()) 
            eig_v.append(vr.copy())
            ef += 1

the output is coming like this for all the modes

abcd
abcd1908×977 101 KB