How to Find What Toolbox a Function is in From Documentation?

Hi,

I hope the answer to this isn't staring me in the face...but I'm trying to use the 'addTerms' function

https://www.mathworks.com/help/stats/linearmodel.addterms.html

and I cannot figure out from the documentation what toolbox I need to download in order to use it.

I already have the 'Statistics and Machine Learning Toolbox' version 12.3. However, my MATLAB install is not recognizing the 'addTerms.m' function.

Thanks for your consideration,

tom

Answer 1

[Matt J]

See the upper-left corner of the doc page. In this case, it is the Statistics and Machine Learning Toolbox.

[Tom Ruopp]

Thanks Matt,

I guess I have a different problem then since I already have that toolbox installed.

Not sure why MATLAB is not letting me use that function...

tom

[Matt J]

I assume you have at least R2012a, which is when it was introduced? And what happens when do,

>>which -all addTerms

[Walter Roberson]

note that addTerms is a method of LinearModel objects, and does not exist for any other kind of input.

[Tom Ruopp]

Matt, I am using R2022a.

Oddly, your suggestion first yielded this:

>> which -all addTerms
C:\Program Files\MATLAB\R2022a\toolbox\simulink\core\general\addterms.p

Then, I just re-did it without changing anything and then got this:

>> which -all addTerms
C:\Program Files\MATLAB\R2022a\toolbox\stats\classreg\+classreg\+regr\TermsRegression.m   % LinearModel method
C:\Program Files\MATLAB\R2022a\toolbox\stats\classreg\+classreg\+regr\FormulaProcessor.m  % classreg.regr.LinearFormula method

So it is being recognized now as a method.

Walter,

I think you solved my confusion. I was attempting to input a cfit object into the command because I am using a nonlinear model in my regression.

Thanks to you both!

[Steven Lord]

Walter is correct. You can see this by scrolling down to the Input Arguments section on that documentation page, which lists as the description of the mdl input argument:

"Linear regression model, specified as a LinearModel object created using fitlm or stepwiselm."

If you tried to call addTerms with something that's not a LinearModel object as the first input, that doesn't satisfy the requirements of the function and so MATLAB throws an error.

[Walter Roberson]

Because it is a class method, MATLAB would not be able to see it at all for other inputs.