我已经从数据库中将一个字符串导入到 R 中。数据库列类型是 BYTEA
(Postgres)。为了让我按预期使用它,它应该是 raw
类型。相反,它是 character
类型。我想在以下意义上将其转换为原始数据:
字符串表示为
\x1f8b080000000000
如果我使用charToRaw
,它会被转换成数组
5c 78 31 66 38 62 30 38
相反,我需要它是数组
1f 8b 08 00 00 00 00 00
我如何实现这一目标。
编辑 #1 回复 Chris
library(RPostgreSQL)
conn <- dbConnect(dbDriver("PostgreSQL"), dbname = "somename",
host = "1.2.3.4", port = 5432,
user = "someuser", password = pw)
some_value <- dbGetQuery(conn, "select value from schema.key_value where key like '%somekey%' limit 1")
some_value$value
# [1] "\\x1f8b080000000000000
最佳答案
这适用于将您所描述类型的单个字符串转换为原始向量。
## The string I think you're talking about
dat <- "\\x1f8b080000000000"
cat(dat, "\n")
## \x1f8b080000000000
## A function to convert one string to an array of raw
f <- function(x) {
## Break into two-character segments
x <- strsplit(x, "(?<=.{2})", perl=TRUE)[[1]]
## Remove the first element, "\\x"
x <- x[-1]
## Complete the conversion
as.raw(as.hexmode(x))
}
## Check that it works
f(dat)
## [1] 1f 8b 08 00 00 00 00 00
关于r - 将原始字节作为 R 中的原始字节导入,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/36343513/