# How to plot points on Bode plot curves

I used BodePlot to plot the magnitude and phase plots for a transfer function Gp1 and I figured out how to add a point to the magnitude (top) plot that is on/follows the curve with:  {x,20 Log10@Abs[Gp1/.s->I x]} but how can I do this for the phase (bottom) plot?

The transfer function I used is:

Gp1 = kc*kp*Exp[-t*s]*(tauI*s + 1)*(tauD*s + 1)/((tauP*s + 1)*tauI*s);
Gp2=TransferFunctionModel[{{Gp1}},s];
t = 1; tauP = 2; tauI = 1; tauD = 3; kp = 8.6; kc = 1;

• Can you include the exact code that generated your plots? Jul 24 '17 at 18:33
• possible duplicate Q/A: Draw line and point into a BodePlot
– kglr
Jul 24 '17 at 19:26

BodePlot[Gp2, {.1, 100}, GridLines -> {{{1}, None}, {{1}, None}},