Calling var(x) on a factor x is defunct when using mice pool function

[bskubi]

I'm using mice and trying to pool the multiple imputations.

#kp is a dataframe with three columns, "x", "Y", and "View". x and Y are numeric, View is class "character"
html <-  read_html("https://wiki.socr.umich.edu/index.php/SOCR_Data_KneePainData_041409")
kp <- html_nodes(html, "table")[[2]] %>%
  html_table()
kp$View <- factor(kp$View)
kp_m <- as.data.frame(kp)
#Some code edited out - I replace values in kp_m with NA because this is for a homework assignment testing multiple imputations. Result is kp_m, a version of kp with 5% of values missing.
kp_i <- mice(kp_m, m=5, maxit=50, meth='pmm', seed=1)
kp_p <- pool(kp_i)

On the call to "pool" above, I get the error:
Calling var(x) on a factor x is defunct. Use something like 'all(duplicated(x)[-1L])' to test for a constant vector. Calls: ... tibble -> tibble_quos -> eval_tidy -> vapply -> FUN -> var

[gerkovink]

I'd suggest looking at the mice vignettes for the proper workflow. You don't seem to be pooling a model.

[jay-sf]

You're right, @gerkovink , however I suggest pool to throw a more useful error message. Please see my answer on Stack Overflow in this context.

[gerkovink]

@jay-sf that's a good point. Wouldn't have guessed this user behaviour for pool(). Will add a more informative error message.

[stefvanbuuren]

Ah, never saw this error before. The error message is best implemented in as.mira() when it sees a mids object.

[gerkovink]

Agreed. Will do.

[stefvanbuuren]

mice 3.13.14 should give the appropriate error message.