plot.mhmm uses global variables instead of variables passed into function if interactive = TRUE

[grahamammal]

While using the CRAN version of this package, if a call to the function plot.mhmm happens with interactive = TRUE is wrapped inside of a function, plot.mhmm looks for global variables for its input instead of the local variables in the function scope. Trying to use variables in the function scope results in the following error:

For example, running:

obs <- seqdef(sapply(1:10, function(i){
  rbinom(10, 2, prob=c(.5, .5))
}))


plot_wrapper <- function(wrapped_model) { 
  plot(wrapped_model, interactive = FALSE)
}          

plot_wrapper(fit_model(build_mmm(obs, n_clusters = 2))$model)

causes the following error:

9.
(function (x, which.plots = NULL, nrow = NA, ncol = NA, byrow = FALSE, 
    row.prop = "auto", col.prop = "auto", layout = "horizontal", 
    pie = TRUE, vertex.size = 40, vertex.label = "initial.probs", 
    vertex.label.dist = "auto", vertex.label.pos = "bottom",  ... 
8.
do.call(mHMMplotgrid, args) 
7.
plot.mhmm(wrapped_model, interactive = FALSE) 
6.
plot(wrapped_model, interactive = FALSE) at .active-rstudio-document#7
5.
plot_wrapper(fit_model(build_mmm(obs, n_clusters = 2))$model) at .active-rstudio-document#10
4.
eval(ei, envir) 
3.
eval(ei, envir) 
2.
withVisible(eval(ei, envir)) 
1.
source("~/.active-rstudio-document", echo = TRUE) 

However if we assign the input of the function to be a global variable, like this instead:

obs <- seqdef(sapply(1:10, function(i){
  rbinom(10, 2, prob=c(.5, .5))
}))


plot_wrapper <- function(wrapped_model) {
  temp <<- wrapped_model
  plot(temp, interactive = FALSE)
}          

plot_wrapper(fit_model(build_mmm(obs, n_clusters = 2))$model)

We get no error.