# plotting logarithmic and linear scale

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Brendan Clark on 11 Apr 2021
Commented: Brendan Clark on 11 Apr 2021
I'm working on an assignment that wants me to create a .m file that graphs both the linear and logarithmic scale.
The assignment is: I have the script doing exactly what I need it to for the linear scale plot, however, I'm not sure how to also get matlab to transition it to log scale for the second set of plots. any help would be useful.
The code I have so far is:
t=linspace(0,20,1000);
speed=188.5*(1-exp(-0.4*t));
torque=10*exp(-0.4*t);
power=torque.*speed;
figure(1)
subplot(3,1,1)
plot(t,torque,'r-','LineWidth',2)
title('\bfPlot of Motor Output Torque\bf\it\tau\rm\bf_{IND},Speed\bf\it\omega_{m},and Power\bf\itP vs Time')
ylabel('\bf\itTorque, \tau\rm\bf_{IND}(N-m)')
grid on
subplot(3,1,2)
plot(t,speed,'r-','LineWidth',2)
grid on
subplot(3,1,3)
plot(t,power,'r-','LineWidth',2)
xlabel('\bfTime,t[s]')
ylabel('\bf\itPower, P\rm\bf(watts)')
grid on
the plots of the log scale should look like this: Andreas Apostolatos on 11 Apr 2021
Hello,
You can use function 'semilogy' for your needs, please visit the following documentation page accordingly,
Simply replace command 'plot' with 'semilogy' and you should already obtain the desirable plots in logarithmic scale.
I hope this helps.
Kind Regards,
Andreas
Brendan Clark on 11 Apr 2021
Thank you! That was exactly what I was missing.