R utility command 2

1. how to temporarily unload the packages in R

> library(Daim)
Loading package: 'Daim'
The following objects are masked from ‘package:pROC’:
   auc, roc
Warning message:
The package 'Daim' was built with R version 3.4.4
> roc
function (x, ...)
UseMethod("roc")
<environment: namespace:Daim>
> library(pROC)
> roc
function (x, ...)
UseMethod("roc")
<environment: namespace:Daim>

use the unloadNamespace("Daim") to unload the Daim package

> unloadNamespace("Daim")
> roc
function (...)
{
    UseMethod("roc")
}
<environment: namespace:pROC>

Daim package has been removed.