how to plot a sequence over a given interval

Hello,

After hours upon hours of trying to work this out and a couple of questions here I am having no luck.

I need to plot a seqeunce over a given interval, I have gotten to the point where the sequence is there however I can't find a way around 'vectors must be the same length'

Here is my code...

n = -20:12
x = repmat([5,4,3,2,1],3 15)
linespace(n)
plot(n,x)

I would expect a saw tooth wave looking graph but I get the above mentioned error.

What am I doing wrong? I don't have enough time to play about with the code to try to figure this out as I need to submit a report tomorrow by 11pmand after trying to figure this out for two or three days I am out of ideas.

Any help will be greatly appriciated.

[Image Analyst]

What is the range of n for just one triangle? How many times do you want to replicate the triangle, and what should be the expected initial and final values of n once the single waveform has been replicated?

[Connor Wright]

Range for n is -20 to 12

number of replications - 5

With initial and final values I honestly am not sure, I would make an ''educated'' guess at -20 for both.

[Image Analyst]

So, n is the x-axis and you want one triangle going from 1 to 5, peaking in the middle, and you want to replicate it 5 more times, for a total of 6 or 198 elements with the final element being n=178?

[Connor Wright]

Yes, as long as that gives me a graph that looks like a saw tooth wave. Its for a Signal Processing lab report based on MATLAB exercises. I can provide the original data from it if that helps.

Answer 1

[Roshan Hingnekar]

In the code mentioned above the length of vector 'n' is 33, the length of vector 'x' is 75, Hence the plot function is giving error.

Use the following code:

n = linspace(-20,12,75);
x = repmat([5,4,3,2,1],3 ,15);
plot(n,x)
xlim([-20 12])

The aboce code should give the saw-tooth output.

[Connor Wright]

Thanks for the help, I ended up using

n = linspace(-20,12,length(x))

Whether or not that is the 'correct' way of doing things is another matter.