[英]install.packages fails in knitr document: "trying to use CRAN without setting a mirror"
Using the following code I got the data I wanted, but for some reason I can't figure out knitr
doesn't let me compile a PDF document, as shown further below:使用下面的代码我得到了我想要的数据,但由于某种原因我无法弄清楚knitr
不允许我编译 PDF 文档,如下所示:
My code:我的代码:
install.packages("weatherData")
library(weatherData)
istanbul <- getWeatherForDate("Istanbul",
start_date = Sys.Date() - 41,
end_date = Sys.Date())
Works out with no problem but I get the following message trying compile the PDF:没有问题,但我在尝试编译 PDF 时收到以下消息:
Quitting from lines 3-31 (ist_weather.spin.Rmd)
Error in contrib.url(repos, type) :
trying to use CRAN without setting a mirror
Calls: <Anonymous> ... eval -> eval -> install.packages -> grep -> contrib.url
Execution halted
Knitr produces a R session, without a default cran mirror unless you specifically asked for one. Knitr 生成一个 R 会话,没有默认的 cran 镜像,除非你特别要求。 We tend to forget we need to set up CRAN for every R session when we use Rstudio because it takes care of it, but only for interactive use, not for knitr.当我们使用 Rstudio 时,我们往往会忘记我们需要为每个 R 会话设置 CRAN,因为它会处理它,但仅用于交互式使用,而不用于 knitr。
You could try specifying a mirror as a install.packages
argument:您可以尝试将镜像指定为install.packages
参数:
install.packages("weatherData",repos = "http://cran.us.r-project.org")
Alternatively, you could set up your default CRAN mirror in your .Rprofile
.或者,您可以在.Rprofile
设置默认的 CRAN 镜像。 See this answer .看到这个答案。
That said, it is not a good idea to install packages through a knitr document that you will probably compile several times .也就是说,通过您可能会多次编译的 knitr 文档安装软件包并不是一个好主意。 You should assume people know how to install a missing package if needed, or at least test whether the package is installed before installing it again如果需要,您应该假设人们知道如何安装丢失的软件包,或者至少在再次安装之前测试该软件包是否已安装
if(!require(weatherData)) install.packages("weatherData",repos = "http://cran.us.r-project.org")
You must set the CRAN repository in your R. To do so, launch R or RStudio.您必须在 R 中设置 CRAN 存储库。为此,请启动 R 或 RStudio。 in the R terminal run following codes.在 R 终端中运行以下代码。
r = getOption("repos")
r["CRAN"] = "http://cran.us.r-project.org"
options(repos = r)
install.packages("weatherData")
Above code defines CRAN repository in the R and in next package installation no need to define again.上面的代码在 R 中定义了 CRAN 存储库,在接下来的包安装中无需再次定义。
Alternative way is to simply run install.packages("weatherData", repos="http://cran.us.r-project.org")
.另一种方法是简单地运行install.packages("weatherData", repos="http://cran.us.r-project.org")
。 However, with the second solution the repository not set and you must pass it as a parameter in every package installation.但是,在第二种解决方案中,未设置存储库,您必须在每个软件包安装中将其作为参数传递。
Honestly,诚实地,
It would not work for me because I installed packages, and these lines of code were interrupting the knit function.它对我不起作用,因为我安装了软件包,而这些代码行中断了 knit 功能。 When I removed all lines containing installing packages (and used the most updated R and R Markdown available) this error went away.当我删除所有包含安装包的行(并使用最新的 R 和 R Markdown 可用)时,此错误消失了。
Ramin Ar's solution worked for me. Ramin Ar 的解决方案对我有用。
Basically, install your packages in the R console, not the R markdown.基本上,将包安装在 R 控制台中,而不是 R 降价。
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