sources.list r安装错误-ubuntu 14.04

我按照书中的指示做了 使用镜子

sources.list文件现在看起来像：

# deb cdrom:[Ubuntu 14.04 LTS _Trusty Tahr_ - Release amd64 (20140417)]/ trusty main restricted

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://sa.archive.ubuntu.com/ubuntu/ trusty main restricted
deb-src http://sa.archive.ubuntu.com/ubuntu/ trusty main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://sa.archive.ubuntu.com/ubuntu/ trusty-updates main restricted
deb-src http://sa.archive.ubuntu.com/ubuntu/ trusty-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://sa.archive.ubuntu.com/ubuntu/ trusty universe
deb-src http://sa.archive.ubuntu.com/ubuntu/ trusty universe
deb http://sa.archive.ubuntu.com/ubuntu/ trusty-updates universe
deb-src http://sa.archive.ubuntu.com/ubuntu/ trusty-updates universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu 
## team, and may not be under a free licence. Please satisfy yourself as to 
## your rights to use the software. Also, please note that software in 
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://sa.archive.ubuntu.com/ubuntu/ trusty multiverse
deb-src http://sa.archive.ubuntu.com/ubuntu/ trusty multiverse
deb http://sa.archive.ubuntu.com/ubuntu/ trusty-updates multiverse
deb-src http://sa.archive.ubuntu.com/ubuntu/ trusty-updates multiverse

## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://sa.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse
deb-src http://sa.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse

deb http://security.ubuntu.com/ubuntu trusty-security main restricted
deb-src http://security.ubuntu.com/ubuntu trusty-security main restricted
deb http://security.ubuntu.com/ubuntu trusty-security universe
deb-src http://security.ubuntu.com/ubuntu trusty-security universe
deb http://security.ubuntu.com/ubuntu trusty-security multiverse
deb-src http://security.ubuntu.com/ubuntu trusty-security multiverse

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
#deb http://archive.canonical.com/ubuntu trusty partner
#deb-src http://archive.canonical.com/ubuntu trusty partner

## This software is not part of Ubuntu, but is offered by third-party
## developers who want to ship their latest software.
deb http://extras.ubuntu.com/ubuntu trusty main
deb http://archive.canonical.com/ trusty partner
#deb-src http://archive.canonical.com/ trusty partner
deb-src http://extras.ubuntu.com/ubuntu trusty main

deb  http://ftp.iitm.ac.in/cran/bin/linux/ubuntu trusty/

在运行sudo apt get update时，我收到了几个错误消息，我认为其中一条是相关的：

Err http://ftp.iitm.ac.in trusty/ Packages 

---

sources.list文件有问题，无法恢复所有存档。我是ubuntu的新手。我该怎么办？

您好，您没有选择cran mirron，它是帮助页面的url。请转到本页并用正确的cran mirror替换，如。如果您选择离您的位置更近的镜像会更好。deb trusty/I将此附加在sources.list中，并且现在已经使用了cran.rstudio，我仍然有相同的错误。恐怕我不明白你的意思？顺便说一下，ftp.iitm.ac.in是离我最近的镜像Indiano，镜像链接的名称必须是完整的示例debhttp://cran.rstudio.com/bin/linux/ubuntu 可信赖的，看看我在之前的消息中发布的链接，选择一个。deb trusty/我已经添加了这个完整的版本，你可以看到我上面给出的sources.list文件的最后一行。我从镜像列表中获得了链接。其中htp://ftp.iiitm.ac.in.cran/ >是为印度列出的链接。