[R] can I call user-created functions without source() ?

Duncan Murdoch murdoch at stats.uwo.ca
Mon Jun 19 16:41:17 CEST 2006

On 6/19/2006 10:19 AM, Joerg van den Hoff wrote:
> Duncan Murdoch wrote:
>> Just a few comments below on alternative ways to do the same things:
>> On 6/19/2006 8:19 AM, Joerg van den Hoff wrote:
>>> for short term usage of some specialized functions I have added some 
>>> lines to the `.Rprofile' in my home(!) directory as follows (probably 
>>> there are smarter solutions, but at least it works):
>>> #source some temporary useful functions:
>>> fl <- dir(path='~/rfiles/current',patt='.*\\.R$',full.names=TRUE)
>>> for (i in fl) {cat(paste('source("',i,'")\n',sep="")); source(i)}
>>> rm(i,fl)
>> Another way to do this without worrying about overwriting some existing 
>> variables is
>> local({
>> fl <- ...
>> for (i in fl) ...
>> })
>> No need to remove fl and i at the end; they were created in a temporary 
>> environment, which was deleted at the end.
> sure, that's better (just one more case, where I did'nt know of the 
> existence of a certain function). but what is the difference (with 
> regards to scope) of `i' or `fl' and the functions defined via sourcing? 
> are'nt both objects defined within `local'? why _are_ the functions 
> visible in the workspace? probably I again don't understand the 
> `eval'/environment intricacies.

Whoops, sorry.  Yes, you'd need to be careful to assign them into 
globalenv().  Those ...'s weren't so simple.

Duncan Murdoch

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