bumbl() assumes there is a switchpoint, doesn't test for one

[Aariq]

bumbl() might fail to find a switchpoint, but it also can find one when there clearly isn't one. For now I'll note this in the documentation, but in the future it would be good to test if the switchpoint model was a better fit than a line, perhaps.

library(bumbl)
library(dplyr)
#> 
#> Attaching package: 'dplyr'
#> The following objects are masked from 'package:stats':
#> 
#>     filter, lag
#> The following objects are masked from 'package:base':
#> 
#>     intersect, setdiff, setequal, union
noswitch <- 
  bombus %>% 
  filter(colony == 9) %>% 
  mutate(d.mass = 0.1)

bumbl(noswitch, colonyID = colony, t = week, formula = d.mass ~ week)
#> # A tibble: 1 x 7
#>   colony converged   tau logN0    logLam    decay logNmax
#>   <chr>  <lgl>     <dbl> <dbl>     <dbl>    <dbl>   <dbl>
#> 1 9      TRUE       4.29 -2.30 -1.63e-16 1.77e-16   -2.30

^{Created on 2021-04-08 by the reprex package (v0.3.0)}