mixedModelDE does not work with a continuous predictor

[lardenoije]

I am working with a GeoMx dataset with contours, similar to what is shown here and would like to analyze these as a continuous gradient. However, the current mixedModelDE function only allows for group comparisons and fails if no groupVar is supplied. It would thus be great if it would also work with continuous predictors.

[NicoleEO]

Thanks @lardenoije for your suggestion. I have added it to our feature requests list.

[lardenoije]

Thanks @NicoleEO! I have in the meantime implemented this in my fork of GeomxTools by adding a continuous option to mixedModelDE, which will allow groupVar to be continuous when TRUE. If you want I can start a pull request, or perhaps it can serve as inspiration.