How to make semilogx to get a plot gain against log frequency with several values?

Gain: 20 log (Vout/Vin) with Vin = 1.0. I've been searching for gain values: a. -156.48 dB b. -80 dB c. -53.98 dB d. -13.98 dB e. 3.52 dB f. 10.32 dB g. 13 dB h. 13.93 dB i. 13.96 dB j. 13.98 dB

I am still at the very start on this semester to learn about matlab. How to make semilogx to get a plot gain against log frequency with several values? I've been searching matlab tutorial but I still got no clues. If anyone could give some explainations or examples relate with this question, please tell me. I want to learn about it. Thank you.

Answer 1

[Aquatris]

Is this what you want;

freq = [2 10 20 60  100 125 150 200 300 400];
Vo   = [0.15e-7 .1e-3 .002 .2 1.5 3.28 4.47 4.97 4.99 5];
Vi   = 10;
Gain = 20*log(Vo/Vi);
semilogx(freq,Gain),grid on