How do I set axis ticks in a graph?

I followed the documentation but it's not working. I'm trying to set the ticks on the graph using xticks(), but Matlab says xticks is an undefined function or variable.

Here's my code:

firstnat = [ntfreq150_1, ntfreq175_1, ntfreq200_1, ntfreq225_1, ntfreq250_1]; 
secondnat = [ntfreq150_2, ntfreq175_2, ntfreq200_2, ntfreq225_2, ntfreq250_2];
Lvec = [150, 175, 200, 225, 250];

Xlabs = [Lvec];
Ylabs = [firstnat, secondnat]; Ylabs = sort(Ylabs); Ylabs = unique(Ylabs);

figure(14)
plot(Lvec, firstnat, 'g', Lvec, secondnat, 'b');
xticks(Xlabs)
yticks(Ylabs)
title('Natural Frequency vs. Length')
xlabel('Length of Beam (mm)')
ylabel('Natural Frequency (Hz)')
legend('First Natural Frequency', 'Second Natural Frequency', 'location', 'northwest')
grid on

firstnat, secondnat, and Lvec are all 1x5 arrays using data from earlier in the script.

Answer 1

[Sayan Saha]

According to the documentation of xticks the function was introduced in MATLAB version R2016b. If you are using a MATLAB version prior to that "xticks" will not work. Instead use the "XTick" property of the axes. For an example refer to:

https://www.mathworks.com/help/releases/R2016a/matlab/ref/axes-properties.html#property_xtick