Hi @Nicholas Scott, it appears that the terms 'Pathology' and 'Cell Line' are highly correlated. In such scenarios, removing one of them should not affect the model. The solve this problem, simply remove the term with lower contribution.
To figure out which terms are contributing more, change the 'sstype' of your 'anovan' function to '1'. This will calculate each term's contribution by adding that term to the terms already included before it. For more information about the 'sstype' refer to the following documentation link: https://www.mathworks.com/help/stats/anovan.html#:~:text=single%20%7C%20double-,sstype,-%E2%80%94%20Type%20of
% To determine the effect of adding Cell Line
pTHalf = anovan(stats(:,1), {Patho CellLine MW},'model','interaction','varnames', ...
{'Pathology','Cell Line','Molecular Weights'}, 'sstype',1);
% To determine the effect of adding Pathology
pTHalf = anovan(stats(:,1), {CellLine Patho MW},'model','interaction','varnames', ...
{'Cell Line','Pathology','Molecular Weights'}, 'sstype',1);
Upon running the above code, it is observed that the 'Pathology' term is not a full rank term, and its F value is far lower than the 'Cell Line' term. Hence removing the 'Pathology' term from the 'anovan' function should remove the issue.
pTHalf = anovan(stats(:,1), {CellLine MW},'model','interaction','varnames', ...
{'Cell Line','Molecular Weights'}, 'sstype',1);
In the above results you can observe that the terms are full ranked and there are no non-full rank terms.
