[R] Changes to stats::glm function between R versions 3.4.0 and 3.5.1

Purver, Mark M@rk@Purver @end|ng |rom Ju@t|ce@gov@uk
Tue Apr 21 19:44:23 CEST 2020

Dear Martin,

Thanks so much for this response. I have attempted a reproducible example below. The 'real' issue involves a much larger data set, but the very small example below produces very small differences in the standard errors between different R versions, which may have the same root cause. I hope to understand whether such differences indicate any change to the 'glm' function between version 3.4.0 of the 'stats' package and later versions. These differences are only apparent when the model does not converge.


dat <- data.frame(
  a = c(1, 3, 8, 9, 2, 3, 4, 5),
  b = c(1, 3, 8, 8, 2, 3, 4, 5),
  x = c(1, 0, 0, 1, 0, 0, 0, 0)

m <- glm(x~a+b, family=binomial(), data=dat)


# Standard errors of variables 'a' and 'b' are 580356.74 and 638232.37 in R 3.4.0, but 580356.25 and 638231.93 in R 3.4.2
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