[R] How to fix offset warning running a GAM in R's MGCV package?

[lauren fidler]

Dear all,

I am trying to run a GAM using MGCV. When I include offset:

gam1 <- gam(Presence~s(Spd)+offset(effort_m), family=binomial, data=porp)

I receive the following warning:

Warning messages:

1: In newton(lsp = lsp, X = G$X, y = G$y, Eb = G$Eb, UrS = G$UrS, L = G$L,  :
  Fitting terminated with step failure - check results carefully
2: glm.fit: fitted probabilities numerically 0 or 1 occurred
3: glm.fit: fitted probabilities numerically 0 or 1 occurred

How can I correct this?

Kind regards,
Lauren

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