Draw a vector from the centroid in point cloud

I have found the centroid and the eigenvectors of a cluster. How can I draw the vector from the centroid in pcl visualizer.

    Eigen::Vector4f centroid;
    Eigen::Matrix3f covariance_matrix;

    // Extract the eigenvalues and eigenvectors
    Eigen::Vector3f eigen_values;
    Eigen::Matrix3f eigen_vectors;

    pcl::compute3DCentroid(*cloud_filtered,cluster_indices[i],centroid);

    // Compute the 3x3 covariance matrix
    pcl::computeCovarianceMatrix (*cloud_filtered, centroid, covariance_matrix);
    pcl::eigen33 (covariance_matrix, eigen_vectors, eigen_values);
    _viewer->addLine<pcl::PointXYZRGB> (centroid, eigen_vectors, "line");