Load R package from character string
I want to create a function which includes loading a package that I make within the function. A short example (which doesn't run!):
loadMe <- function(name){
genLib(xxx, libName = name) #make a new library with name "name"
library(name) #load the new library...
}
This does not work! A bit of reproducible code which illustrates my main problem:
library(ggplot) #this works fine
load.this <- "ggplot"
library(load.this) #I want this to load ggplot!
I know the problem is that library()
开发者_StackOverflow and require()
take as an argument an object name which does not exist yet. I have tried wrapping my character string with parse()
, deparse()
, substitute()
, expression()
, quote()
, etc etc. These all return the same problem:
library(load.this)
# Error in library(loadss) : there is no package called 'loadss'
library(deparse(load.this))
# Error in library(deparse(loadss)) : 'package' must be of length 1
Is there a way to do this?
Use the character.only
argument
foo <- "ggplot2"
library(foo,character.only=TRUE)
You say that you have tried using parse()
. The following seems to work for me:
eval(parse(text = 'library(MASS)')[1])
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