Plotting certain values of a matrix

Hello I have a 100x1 matrix and would like to plot n=2 and n=100 values against x how would I go about doing this? Thanks for any help

Answer 1

[madhan ravi]

plot(repmat(100,100,1),x)
%           ^^^-—-—-n
hold on
plot(repmat(2,100,1),x)

[Josh]

How do I use my N=100x1 matrix in this method?

[madhan ravi]

Not clear what your trying to do.

[Josh]

I have a matrix 'N' which is 100x1, I would like to plot the second and last value against x. How do I do this?

[madhan ravi]

size(x) ?

plot(N([1 end]),x([1 end]))

[Josh]

Sorry I don't follow, it didn't seem to work, what do the 1's and end's do? Sorry very new to Matlab.

[madhan ravi]

Sorry it was supposed to be :

[2 end] % second and last element

To learn the basics:https://in.mathworks.com/company/newsletters/articles/matrix-indexing-in-matlab.html

[Josh]

Thanks think I got it now. Sorry one more thing, how could I add another line to this plot? eg: 'y' It is a bit confusing.

[madhan ravi]

https://in.mathworks.com/help/matlab/ref/linespec.html

'y' represents color of the plot which is yellow.

See my original answer after using hold on plot another line to the same figure

doc hold
doc plot

I suggest you to do MATLAB onramp course which is free and takes few hours to complete by then you will get know the basics of MATLAB.

[Josh]

Thanks for the help