Search code examples
rscoping

attach() inside function

I'd like to give a params argument to a function and then attach it so that I can use a instead of params$a everytime I refer to the list element a.

run.simulation<-function(model,params){
attach(params)
#
# Use elements of params as parameters in a simulation
detach(params)
}

Is there a problem with this? If I have defined a global variable named c and have also defined an element named c of the list "params" , whose value would be used after the attach command?

Solution

  • Noah has already pointed out that using attach is a bad idea, even though you see it in some examples and books. There is a way around. You can use "local attach" that's called with. In Noah's dummy example, this would look like

    with(params, print(a))

    which will yield identical result, but is tidier.