Modeling functions have problems with environments of custom transformations

When using custom transformation functions (like my_scaled_logit() below), the modeling functions like ETS() or ARIMA() seem to search only the global environment for their definition. When run inside a different environment, an error is thrown, see below.

The problem is best illustrated in the example below, I think. However, I actually ran into this when rendering an RMarkdown document using rmarkdown::render(envir = new.env()).

library("fpp3")

df1 <- dplyr::filter(prices, !is.na(eggs))

f1 <- function(data = NULL) {

    my_scaled_logit <- fabletools::new_transformation(
        transformation = function(x, lower = 10, upper = 400) {
            log((x - lower) / (upper - x))
        },
        inverse = function(x, lower = 10, upper = 400) {
            (upper - lower) * exp(x) / (1 + exp(x)) + lower
        }
    )

    data %>%
        model(ETS(my_scaled_logit(eggs)))
}

f1(df1)
#> Error in get("my_scaled_logit"): object 'my_scaled_logit' not found

^{Created on 2021-02-18 by the reprex package (v1.0.0)}

Session info

``` r sessioninfo::session_info() #> - Session info --------------------------------------------------------------- #> setting value #> version R version 4.0.3 (2020-10-10) #> os Windows 10 x64 #> system x86_64, mingw32 #> ui RTerm #> language (EN) #> collate German_Germany.1252 #> ctype German_Germany.1252 #> tz Europe/Berlin #> date 2021-02-18 #> #> - Packages ------------------------------------------------------------------- #> package * version date lib source #> anytime 0.3.9 2020-08-27 [1] CRAN (R 4.0.2) #> assertthat 0.2.1 2019-03-21 [1] CRAN (R 4.0.0) #> backports 1.2.1 2020-12-09 [1] CRAN (R 4.0.3) #> cli 2.3.0 2021-01-31 [1] CRAN (R 4.0.3) #> colorspace 2.0-0 2020-11-11 [1] CRAN (R 4.0.3) #> crayon 1.4.1 2021-02-08 [1] CRAN (R 4.0.3) #> DBI 1.1.1 2021-01-15 [1] CRAN (R 4.0.3) #> digest 0.6.27 2020-10-24 [1] CRAN (R 4.0.3) #> distributional 0.2.2 2021-02-02 [1] CRAN (R 4.0.3) #> dplyr * 1.0.4 2021-02-02 [1] CRAN (R 4.0.3) #> ellipsis 0.3.1 2020-05-15 [1] CRAN (R 4.0.2) #> evaluate 0.14 2019-05-28 [1] CRAN (R 4.0.0) #> fable * 0.3.0 2021-02-03 [1] CRAN (R 4.0.3) #> fabletools * 0.3.0 2021-01-19 [1] CRAN (R 4.0.3) #> farver 2.0.3 2020-01-16 [1] CRAN (R 4.0.0) #> feasts * 0.1.7 2021-02-05 [1] CRAN (R 4.0.3) #> fpp3 * 0.4.0 2021-02-06 [1] CRAN (R 4.0.3) #> fs 1.5.0 2020-07-31 [1] CRAN (R 4.0.2) #> generics 0.1.0 2020-10-31 [1] CRAN (R 4.0.3) #> ggplot2 * 3.3.3 2020-12-30 [1] CRAN (R 4.0.3) #> glue 1.4.2 2020-08-27 [1] CRAN (R 4.0.2) #> gtable 0.3.0 2019-03-25 [1] CRAN (R 4.0.0) #> highr 0.8 2019-03-20 [1] CRAN (R 4.0.0) #> htmltools 0.5.1.1 2021-01-22 [1] CRAN (R 4.0.3) #> knitr 1.31 2021-01-27 [1] CRAN (R 4.0.3) #> lifecycle 0.2.0 2020-03-06 [1] CRAN (R 4.0.0) #> lubridate * 1.7.9.2 2020-11-13 [1] CRAN (R 4.0.3) #> magrittr 2.0.1 2020-11-17 [1] CRAN (R 4.0.3) #> munsell 0.5.0 2018-06-12 [1] CRAN (R 4.0.0) #> pillar 1.4.7 2020-11-20 [1] CRAN (R 4.0.3) #> pkgconfig 2.0.3 2019-09-22 [1] CRAN (R 4.0.0) #> progressr 0.7.0 2020-12-11 [1] CRAN (R 4.0.3) #> ps 1.5.0 2020-12-05 [1] CRAN (R 4.0.3) #> purrr 0.3.4 2020-04-17 [1] CRAN (R 4.0.0) #> R6 2.5.0 2020-10-28 [1] CRAN (R 4.0.3) #> Rcpp 1.0.6 2021-01-15 [1] CRAN (R 4.0.3) #> reprex 1.0.0 2021-01-27 [1] CRAN (R 4.0.3) #> rlang 0.4.10 2020-12-30 [1] CRAN (R 4.0.3) #> rmarkdown 2.6 2020-12-14 [1] CRAN (R 4.0.3) #> rstudioapi 0.13 2020-11-12 [1] CRAN (R 4.0.3) #> scales 1.1.1 2020-05-11 [1] CRAN (R 4.0.0) #> sessioninfo 1.1.1 2018-11-05 [1] CRAN (R 4.0.2) #> stringi 1.5.3 2020-09-09 [1] CRAN (R 4.0.2) #> stringr 1.4.0 2019-02-10 [1] CRAN (R 4.0.0) #> styler 1.3.2 2020-02-23 [1] CRAN (R 4.0.0) #> tibble * 3.0.6 2021-01-29 [1] CRAN (R 4.0.3) #> tidyr * 1.1.2 2020-08-27 [1] CRAN (R 4.0.2) #> tidyselect 1.1.0 2020-05-11 [1] CRAN (R 4.0.0) #> tsibble * 0.9.3 2020-10-06 [1] CRAN (R 4.0.3) #> tsibbledata * 0.2.0 2020-06-04 [1] CRAN (R 4.0.3) #> vctrs 0.3.6 2020-12-17 [1] CRAN (R 4.0.3) #> withr 2.4.1 2021-01-26 [1] CRAN (R 4.0.3) #> xfun 0.21 2021-02-10 [1] CRAN (R 4.0.3) #> yaml 2.2.1 2020-02-01 [1] CRAN (R 4.0.2) #> #> [1] D:/Users/BKU/HansjoergPlieninger/Documents/R/win-library/4.0 #> [2] D:/Users/BKU/HansjoergPlieninger/Documents/R/R-4.0.3/library ```

I don't know whether this is related to tidyverts/fable#80, but I'm referencing it here in case it is.

tidyverts / fabletools

Modeling functions have problems with environments of custom transformations #311