install R 4.0 in ubuntu

#1 清除R3先

sudo apt-get --purge remove r-base

sudo apt-get --purge remove r-base-core

sudo apt-get --purge remove r-base-dev

#2 升级系统

sudo apt install --fix-missing libcurl4-openssl-dev libxml2-dev libgdal-dev libssl-dev libglu1-mesa-dev libmagick++-dev libudunits2-dev 

sudo apt install -y libcurl4-gnutls-dev
sudo apt install -y  libxml2-dev
sudo apt install -y  openssl 
sudo apt install -y  libssl-dev

#3 安装R4

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys E298A3A825C0D65DFD57CBB651716619E084DAB9
sudo add-apt-repository ‘deb https://mirrors.ustc.edu.cn/CRAN/bin/linux/ubuntu focal-cran40/‘
sudo apt update
sudo apt install r-base

# 查看R安装选择
apt-cache policy r-base r-base-core r-base-dev r-recommended