Help with Linear mixed effects Model (LME)

Hi! I have a complicated dataset of biomechanical analysis where I am looking at different joint angles and the way they change over time (in % of of cycle) in different conditions (2 types). I need to investigate the influence of subjects (3 of them) and timepoint (1 to 101) on the data. I want to regress angle on condition.

I have prepared an a table with the variables for lme.

lme = fitlme(tbl,'Angle~Condition+(1|Subject)+(Conditon-1|Subject)');

Condition and Subject are categorical data on tbl.

When I run this line I keep getting the error message:_

"Class 'classreg.regr.LinearLikeMixedModel' is not an allowed subclass of class 'classreg.regr.ParametricRegression'.

Error in fitlme (line 224) lme = LinearMixedModel.fit(ds,formula,varargin{:});"

Any help on modelling this and why I am getting this error?

Thanks

Answer 1

[Paul]

Hi Luís,

That's a rather unfamiliar error to me. Could you provide the code you use to produce the table and some portion of the contents of the table so I might reproduce the error?

Also, how many datapoints (rows) are in your table?

And did all three subjects provide data for both conditions?

Also, I believe your formula can be simplified to 'Angle ~ Condition + (Condition|Subject)'. Is there any particular reason you have it formulated the way you did?

Best,

Paul