Summary: A method for visualization of dynamic multidimensional data-$L$-plotting, similar to recurrence plotting, is described. For multi-neuronal brainstem recordings the method demonstrates that the neural respiratory pattern generator (RPG) switches between the two phases: inspiratory and expiratory. The method helps to mark phase switching moments and to characterize the pattern of the RPG restart after temporary cessation of rhythmicity. Comparison of $L$-plots for experimental data and network simulations helps verification of computational models.