将integer64转换为R中的整数

Question

我正在研究一个几周前开始的密码。但是，(我不知道为什么)代码突然将一些列转换为integer64格式。使用这种格式，代码的其余部分不再运行，我也不熟悉integer64格式。我只想将integer64列转换为整数或数字格式。通常的命令as.numeric或as.integer不能工作。我能做什么?

这里是我的数据的一个示例

> dput(head(my_data3, n = 30))
structure(list(year = c(2007, 2009, 2011, 2012, 2005, 2017, 2001, 
2004, 2005, 2006, 2007, 2008, 2010, 2011, 2012, 2013, 2014, 2016, 
2017, 2018, 2018, 2011, 2014, 2002, 2015, 2004, 2008, 2009, 2011, 
2012), export_value = structure(c(0, 0, 0, 0, 5.74548939548786e-319, 
3.29556607745487e-319, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2.20704064653743e-319, 
0, 0, 0, 3.13731685109192e-320, 3.82307996751957e-320, 0, 0, 
1.39406056696212e-318, 7.3185450052818e-319, 1.72873569479852e-320, 
7.06760906375903e-320, 1.04667807071468e-319, 2.30382810655773e-320, 
1.01915861424132e-319), class = "integer64"), location_code = c("AGO", 
"AGO", "AGO", "AGO", "MDG", "MDG", "MOZ", "MOZ", "MOZ", "MOZ", 
"MOZ", "MOZ", "MOZ", "MOZ", "MOZ", "MOZ", "MOZ", "MOZ", "MOZ", 
"MOZ", "SWZ", "SYC", "SYC", "TZA", "TZA", "ZAF", "ZAF", "ZAF", 
"ZAF", "ZAF"), partner_code = c("AFG", "AFG", "AFG", "AFG", "AFG", 
"AFG", "AFG", "AFG", "AFG", "AFG", "AFG", "AFG", "AFG", "AFG", 
"AFG", "AFG", "AFG", "AFG", "AFG", "AFG", "AFG", "AFG", "AFG", 
"AFG", "AFG", "AFG", "AFG", "AFG", "AFG", "AFG"), export_destination = c("RoW", 
"RoW", "RoW", "RoW", "RoW", "RoW", "RoW", "RoW", "RoW", "RoW", 
"RoW", "RoW", "RoW", "RoW", "RoW", "RoW", "RoW", "RoW", "RoW", 
"RoW", "RoW", "RoW", "RoW", "RoW", "RoW", "RoW", "RoW", "RoW", 
"RoW", "RoW"), product_group = c("Food", "Food", "Food", "Food", 
"Food", "Food", "Food", "Food", "Food", "Food", "Food", "Food", 
"Food", "Food", "Food", "Food", "Food", "Food", "Food", "Food", 
"Food", "Food", "Food", "Food", "Food", "Food", "Food", "Food", 
"Food", "Food"), exporter = c("Angola", "Angola", "Angola", "Angola", 
"Madagascar", "Madagascar", "Mozambique", "Mozambique", "Mozambique", 
"Mozambique", "Mozambique", "Mozambique", "Mozambique", "Mozambique", 
"Mozambique", "Mozambique", "Mozambique", "Mozambique", "Mozambique", 
"Mozambique", "Eswatini", "Seychelles", "Seychelles", "Tanzania", 
"Tanzania", "South Africa", "South Africa", "South Africa", "South Africa", 
"South Africa"), export_destination_country = c("Afghanistan", 
"Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", 
"Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", 
"Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", 
"Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", 
"Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", 
"Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan")), row.names = c(NA, 
-30L), class = c("data.table", "data.frame"), .internal.selfref = <pointer: 0x00000295b7981ef0>)

Answer 1

integer64类由teh bit64包创建。有many questions that have arisen over the years that have been answered on SO。需要通过使用创建integer64对象的包中的函数来恢复数据而不损坏数据。

 library(bit64)
 ?integer64
 # You might imagine that as.numeric should have an integer64 method.
 # ....  but like me you would have been wrong
 #Instead, division is defined for integer64 objects and it returns a double.
 # .... so divide by 1 ( if and only if you have installed and loaded pkg:bit64

  my_data3$export_value/1
 [1]      0      0      0      0 116290  66703      0      0      0      0      0      0      0      0      0  44671
 [17]      0      0      0   6350   7738      0      0 282161 148129   3499  14305  21185   4663  20628

我之前没有注意到，as.integer和as.double泛型都是为'integer64‘对象定义的，所以最好使用它们。当然，如果需要一个整数，最好从as.integer开始。

我想早期的一个或多个问题和答案可能包含了这个问题的答案，但在我看的第五个问题中，我没有遇到一个重复的答案。