Improve environments in special evaluation

[mitchelloharawild]

library(fable)
gasoline <- as_tsibble(fpp2::gasoline)

get_cv <- function(knots, K) {
  browser()
  gasoline %>% 
    model(TSLM(value ~ fourier(K = K) + trend(knots))) %>% 
    glance() %>% 
    pull(CV)
}
cvk <- numeric(25)
for(k in seq(25))
  cvk[k] <- optim(c(800,1100), get_cv, K=k)$value
K <- which.min(cvk)