在编写自己的 R 包时，我似乎无法正确导入其他包 [英] When writing my own R package, I can't seem to get other packages to import correctly

问题描述

好的，第一次尝试编写 R 包，我被卡住了.这是我创建包的方式:

package.skeleton("pkg",code_files=some.filenames)roxygenize(okg")

我正在使用 roxygen2 并且在我的pkg-package.R"文件中有以下导入:

@import data.table zoo lubridate

然后从终端运行:

R CMD 构建包R CMD 检查包R CMD 安装包

在检查阶段，我收到以下警告:

<块引用>

** 为延迟加载准备包
警告:加载lubridate"时替换先前导入的小时"
警告:加载‘lubridate’时替换之前的导入‘mday’
警告:加载‘lubridate’时替换之前的导入‘month’
警告:加载‘lubridate’时替换之前的导入‘wday’
警告:加载‘lubridate’时替换上一个导入‘week’
警告:加载‘lubridate’时替换之前的导入‘yday’
警告:加载lubridate"时替换以前的导入年份"
** 帮助
* 安装帮助索引
** 构建包索引...
** 测试是否可以加载已安装的包
警告信息:
1:在加载‘lubridate’时替换之前导入的‘hour’
2:在加载‘lubridate’时替换之前的导入‘mday’
3: 加载‘lubridate’时替换之前导入的‘month’
4:在加载‘lubridate’时替换之前的导入‘wday’
5:在加载‘lubridate’时替换之前导入的‘week’
6:在加载‘lubridate’时替换之前的导入‘yday’
7:加载‘lubridate’时替换之前导入的‘year’

我真的不知道该怎么做，但它们看起来像是覆盖命名空间中的东西的典型警告.在任何情况下，我都可以安装该软件包，但是当我尝试使用它时会发生以下情况:

<块引用><块引用>

库(pkg)
覆盖 POSIXt、Date 和 difftime 的 + 和 - 方法
警告信息:
1:在加载‘lubridate’时替换之前导入的‘hour’
2:在加载‘lubridate’时替换之前的导入‘mday’
3: 加载‘lubridate’时替换之前导入的‘month’
4:在加载‘lubridate’时替换之前的导入‘wday’
5:在加载‘lubridate’时替换之前导入的‘week’
6:在加载‘lubridate’时替换之前的导入‘yday’
7:在加载‘lubridate’时替换之前导入的‘year’
d <- my.function(arg1, arg2)
MATCH(x, x) 中的错误:找不到函数MATCH"

使用 traceback()，我发现这是在调用 merge.zoo() 期间生成的.所以我尝试在 R 会话期间手动加载 zoo，瞧，然后该功能正常运行，没有错误消息.

我已经尝试在pkg-package.R"文件和 NAMESPACE 中手动更改导入的顺序.然而，根据我在其他地方找到的内容，我没有在描述中添加任何导入或依赖.有帮助吗?

解决方案

警告是因为data.table和lubridate都定义了一个符号hour等；参见 data.table::hour 和 lubridate::hour.您可以通过仅从 lubridate/data.table 导入您想要的函数而不是整个包来避免这种情况；标准 NAMESPACE 文件将包含

importFrom(lubridate, 小时)

例如.在 roxygen2 中，您将使用标签:

@importFrom 润滑小时

MATCH 问题可能是因为 merge 的调度不正确，可能是因为 zoo 应该在其名称空间中使用 S3method(merge, zoo) 而不是 export(merge.zoo)，如编写 R 扩展，1.6.2 中所述.这里的解决方案是联系 zoo 的维护者，packageDescription('zoo')$Maintainer(维护者对 R 非常精通，我觉得我错了-确诊...).

Alright, first attempt at writing an R package and I'm stuck. Here's how I create the package:

package.skeleton("pkg",code_files=some.filenames)
roxygenize("okg")

I'm using roxygen2 and have the following imports in my "pkg-package.R" file:

@import data.table zoo lubridate

From a terminal, I then run:

R CMD build pkg
R CMD check pkg
R CMD install pkg

During the check phase, I get the following warnings:

** preparing package for lazy loading
Warning: replacing previous import ‘hour’ when loading ‘lubridate’
Warning: replacing previous import ‘mday’ when loading ‘lubridate’
Warning: replacing previous import ‘month’ when loading ‘lubridate’
Warning: replacing previous import ‘wday’ when loading ‘lubridate’
Warning: replacing previous import ‘week’ when loading ‘lubridate'
Warning: replacing previous import ‘yday’ when loading ‘lubridate’
Warning: replacing previous import ‘year’ when loading ‘lubridate’
** help
* installing help indices
** building package indices ...
** testing if installed package can be loaded
Warning messages:
1: replacing previous import ‘hour’ when loading ‘lubridate’
2: replacing previous import ‘mday’ when loading ‘lubridate’
3: replacing previous import ‘month’ when loading ‘lubridate’
4: replacing previous import ‘wday’ when loading ‘lubridate’
5: replacing previous import ‘week’ when loading ‘lubridate’
6: replacing previous import ‘yday’ when loading ‘lubridate’
7: replacing previous import ‘year’ when loading ‘lubridate’

I'm really not sure what to make of those, but they seem like typical warnings from overwriting stuff in namespace. In any case, I am able to install the package, but here's what happens when I try to use it:

library(pkg)
Overriding + and - methods for POSIXt, Date and difftime
Warning messages:
1: replacing previous import ‘hour’ when loading ‘lubridate’
2: replacing previous import ‘mday’ when loading ‘lubridate’
3: replacing previous import ‘month’ when loading ‘lubridate’
4: replacing previous import ‘wday’ when loading ‘lubridate’
5: replacing previous import ‘week’ when loading ‘lubridate’
6: replacing previous import ‘yday’ when loading ‘lubridate’
7: replacing previous import ‘year’ when loading ‘lubridate’
d <- my.function(arg1, arg2)
Error in MATCH(x, x) : could not find function "MATCH"

Using traceback(), I found out that this is being generating during a call to merge.zoo(). So I tried loading zoo by hand during my R session and voila, then the function works correctly without the error message.

I have tried changing the ordering of the imports by hand in both the "pkg-package.R" file, as well as in NAMESPACE. Based on something I found elsewhere, I have not added any Imports or Depends to DESCRIPTION, however. Help?

解决方案

The warnings are because data.table and lubridate both define a symbol hour, etc; see data.table::hour and lubridate::hour. You could avoid this by importing just the functions from lubridate / data.table that you want, rather than the whole package; a standard NAMESPACE file would contain

importFrom(lubridate, hour)

for instance. In roxygen2 you would use the tag:

@importFrom lubridate hour

The MATCH problem is probably because merge is dispatching incorrectly, probably because zoo should have in its name space S3method(merge, zoo) rather than export(merge.zoo), as described in Writing R Extensions, 1.6.2. The solution here is to contact the maintainer of zoo, packageDescription('zoo')$Maintainer (the maintainer is sufficiently versed in R that I feel like I've mis-diagnosed...).

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