def print_header(npart, niter, tol_type, tlevels, priors):
    """print header to screen
        Input:
        npart - number of particles
        niter - number of iterations
        tol_type - decreasing tolerance level setting
        tlevels - max/min threshold levels
        priors - priors for parameters
        """
    print('\t \t')
    print(
        '\t ########################     astroABC     ########################\t'
        )
    print('\t \t')
    print('\t Npart=%d \t numt=%d \t tol=[%.4f,%.4f] %s' % (npart, niter,
        tlevels[0], tlevels[1], tol_type))
    print('\t Priors=', priors)
