REEMForest() 'Error in solve.default(S1) : Lapack routine dgesv: system is exactly singular:'

[JustGettinStarted]

REEMForest() consistently produces an error with with several different datasets. Seems to be coming from solve() in moy() functions. This appears to be common problem. See https://stackoverflow.com/questions/66188123/implementing-longitudinal-random-forest-with-longiturf-package-in-r and answer 1 to https://stats.stackexchange.com/questions/103730/how-can-i-include-random-effects-or-repeated-measures-into-a-randomforest

[Chhr1s]

Hi @JustGettinStarted,

I've been working with LongituRF for a project over the past week and had the same problem as you.

I modified the function and had it print in-between steps. It seems (for me) the issue was with the output from calling the internal function LongituRF:::logV().

I looked at the data from the simulated case, as that was working just fine for me. I tried centering and scaling the continuous predictors and everything worked for me! Try applying that.

If you're trying to be very rigorous, care should be taken to prevent leakage of information between training and test sets during the scaling process.

More helpful warning messages would be a big improvement here.

[Chhr1s]

I'm going to come back to this and say I got REEMforest() to work in really specific cases, but I've run into this many more (if not most) times as I keep working with it. Same error @JustGettinStarted described above.

MERF() appears to have fewer problems.

[isaactpetersen]

I run into this issue every time as well, including with MERF().