Figure 2From: Existence of order-1 periodic solutions for a viral infection model with state-dependent impulsive controlThe general location of the characteristic points. (a) \(x^{*}< h\); (b) \(h< x^{*}<\bar{h}\), the trajectory from \(P_{0}\) can hit the line \(x=h\); (c) \(h< x^{*}<\bar{h}\), the trajectory from \(P_{0}\) cannot hit the line \(x=h\)Back to article page