How to find values from a bode plot

How would I find find these values from a bode plot in matlab for a transfer function

GAIN MARGIN(dB) - used to determine kcrit = 10^(gain margin/20)

wcrit = w(rads/s) at gain margin

Answer 1

[Rajat Tewari]

You can refer to margin function which helps to calculate Gain and Phase Margin.