linprog example returns empty vector (when it should return 0.6667 1.3333)

Running this example https://www.mathworks.com/help/optim/ug/linprog.html#buus0qo-2

just gives me x =[] what gives I should be getting

Optimal solution found.

x = 2×1

0.6667

1.3333

[Hao Sun]

Okay I think this is because there is another linprog in C:\Program Files\Mosek\8\toolbox\r2014a idk where this came from or how to get rid of it / deal with it.

[John D'Errico]

How to get rid of it? Um, you created a file with that name, then saved it on your search path. Don't do that?

It is legal to delete or rename a file that you created.

In general, it is a bad idea to create files with the same name as MATLAB functions that you will later be using. Else, you will have this exact problem.

[Hao Sun]

I don't think I created that file I think it just got installed when I installed certain matlab packages or something. Btw if I cannot delete the file directly ( I don't have administrative access I use matlab on campus as a student) what can I do? Also what can I do to prevent overriding these defaults when installing packages?

Answer 1

[Stephen23]

"...I think it just got installed when I installed certain matlab packages or something."

It looks like some badly-written third-party toolboxes are shadowing the inbuilt function name/s.

" Also what can I do to prevent overriding these defaults when installing packages?"

You could:

• delete those toolboxes (but usually users want to keep toolboxes), or
• rename those functions (this might not be a trivial task), or
• change the path order so that inbuilt toolboxes have a higher priority (but this could break functionality of those badly-written third-party toolboxes), or
• remove those toolboxes from the Search Path:

https://www.mathworks.com/help/matlab/matlab_env/what-is-the-matlab-search-path.html

For example, you could use restoredefaultpath to reset back to the default Search Path:

https://www.mathworks.com/help/matlab/ref/restoredefaultpath.html