Undefined function 'xline' for input arguments of type 'double'.

Have been working on a project on my laptop and university computer and when I sent over my data the 'xline' function no longer worked on the matlab file and renders the error - "Undefined function 'xline' for input arguments of type 'double'." and is not working for any value of xline(x1) that I enter on the computer.

[Setsuna Yuuki.]

Are you sure your arguments are valid?

%for example:
xline(1);

Answer 1

[Jon]

Is it possible that the university computer is running an outdated version of MATLAB? According to the documentation xline was introduced in 2018b. Type ver on the command line to see what version you are running. Otherwise it could be a path problem. Make sure that the directory where the xline.m file is found, e.g. C:\Program Files\MATLAB\R2020a\toolbox\matlab\specgraph\xline.m, is on the MATLAB path.

[Jon]

If you can't solve the problem a work around would be to just plot for example

xval = 3;  % or wherever you want your vertical line to be
bigY = 1000; % something that is bigger than your typical range of y values
plot(x,y,[xval;xval],[-bigY,bigY]) % assume x and y defined previously
ylim([0,10]); % set limits appropriately to clip off excess y values on vertical line

[Jonah Bricknell]

Cheers Jon , this worked perfectly

[Jon]

Excellent - glad to hear

Answer 2

[Ameer Hamza]

xline() was introduced in R2018b. If you are using an older release, you will get this error.

[Jonah Bricknell]

Oh that makes sence, have been stuck on this for a while.

Is there another way of making a vertical line from a chosen x value for an older version, along with other data on the same graph?

[Jon]

please see my answer below

[Jonah Bricknell]

Yeah checked your answer Jon;

Thanks Ameer