How to turn gpclibPermit() to TRUE

Question

When I run gpclibPermit(), I've got the answer FALSE. How can I change it to be TRUE?

Macmillan

You need to have the gpclib package installed. – Disrate

Answer 1

I've struggled with the gpclibPermit issue myself. You don't provide a reproducible example, but I am guessing that you are having a sesion like this:

library(maptools)
Checking rgeos availability: FALSE
Note: when rgeos is not available, polygon geometry computations in maptools depend 
    on gpclib, which has a restricted licence. It is disabled by default;
to enable gpclib, type gpclibPermit()
> gpclibPermitStatus()
[1] FALSE
> gpclibPermit()
[1] FALSE
> gpclibPermitStatus()
[1] FALSE

At this point it helps to look at what gpclibPermit and gpclibPermitStatus actually do:

> gpclibPermit
function ()  
{
if ("gpclib" %in% .packages(all.available = TRUE)) 
    assign("gpclib", TRUE, envir = .MAPTOOLS_CACHE)
if (gpclibPermitStatus()) 
    warning("support for gpclib will be withdrawn from maptools at the next major release")
gpclibPermitStatus()
}
<environment: namespace:maptools>
> gpclibPermitStatus
function () 
    get("gpclib", envir = .MAPTOOLS_CACHE)
<environment: namespace:maptools>

That is, you can't give maptools the permission to use gpclib unless you have the package gpclib installed.

install.packages("gpclib")
library(maptools)
Loading required package: sp
Checking rgeos availability: FALSE
Note: when rgeos is not available, polygon geometry computations in maptools depend on gpclib,  which has a restricted licence. It is disabled by default; to enable gpclib, type gpclibPermit()

> gpclibPermit()
[1] TRUE
Warning message:
In gpclibPermit() :
support for gpclib will be withdrawn from maptools at the next major release
> gpclibPermitStatus()
[1] TRUE

Stilbite

Answer 2

I had this issue myself and found it easiest to install rgeos, and ensure that it was attached prior to attaching maptools

library(ggplot2)
library(rgeos)
library(maptools)

Redraft

Nicely done solution resolves the gpclibPermit = FALSE message – Dev