如何将字符向量拆分为数据框？

Question

我对R还是比较新的,希望你能再次帮助我.我有一个长度为42000的字符向量.向量看起来像这样:

a <- c("blablabla-19960101T000000Z-1.tsv", "blablabla-19960101T000000Z-2.tsv", "blablabla-19960101T000000Z-3.tsv")

我想将矢量分割成一个如下所示的数据框:

Name        Date          no
blablabla   1996-01-01    1
blablabla   1996-01-01    2
blablabla   1996-01-01    3

我正在努力分裂和创建我的数据框.有人可以帮我弄这个吗？谢谢!

Answer 1

DF <- data.frame(do.call(rbind, strsplit(a, "-", fixed=TRUE)))
DF[,2] <- as.Date(DF[,2] , format="%Y%m%d")
DF[,3] <- as.integer(gsub(".tsv", "", DF[,3], fixed=TRUE))

#         X1         X2 X3
#1 blablabla 1996-01-01  1
#2 blablabla 1996-01-01  2
#3 blablabla 1996-01-01  3

Answer 2

也许有

library(reshape2)
colsplit(a, "\\-", names=c("A", "B", "C"))

          A                B     C
1 blablabla 19960101T000000Z 1.tsv
2 blablabla 19960101T000000Z 2.tsv
3 blablabla 19960101T000000Z 3.tsv

要么

b <- colsplit(a, "[[:punct:]]|\\T|\\.", names=c("A", "B", "C", "D","E"))

          A        B       C D   E
1 blablabla 19960101 000000Z 1 tsv
2 blablabla 19960101 000000Z 2 tsv
3 blablabla 19960101 000000Z 3 tsv

然后

library(lubridate)
b$B <- ymd(b$B)

          A          B       C D   E
1 blablabla 1996-01-01 000000Z 1 tsv
2 blablabla 1996-01-01 000000Z 2 tsv
3 blablabla 1996-01-01 000000Z 3 tsv

str(b)
'data.frame':   3 obs. of  5 variables:
 $ A: chr  "blablabla" "blablabla" "blablabla"
 $ B: POSIXct, format: "1996-01-01" "1996-01-01" "1996-01-01"
 $ C: chr  "000000Z" "000000Z" "000000Z"
 $ D: int  1 2 3
 $ E: chr  "tsv" "tsv" "tsv"

Answer 3

您几乎可以直接使用read.table，但您的日期格式与 R 用于参数的格式不同colClasses。

没问题。只需指定您自己的class并继续:-)

## Create a class called "ymdDate"
setClass("ymdDate")
setAs("character", "ymdDate", function(from) as.Date(from, format="%Y%m%d"))

## Use `read.table` on your character vector. For convenience, I've
##   used `gsub` to get rid of the `.tsv` in before reading it in.
out <- read.table(text = gsub(".tsv$", "", a), header = FALSE, 
                  sep = "-", colClasses=c("character", "ymdDate", "integer"))
out
#          V1         V2 V3
# 1 blablabla 1996-01-01  1
# 2 blablabla 1996-01-01  2
# 3 blablabla 1996-01-01  3
str(out)
# 'data.frame':  3 obs. of  3 variables:
#  $ V1: chr  "blablabla" "blablabla" "blablabla"
#  $ V2: Date, format: "1996-01-01" "1996-01-01" "1996-01-01"
#  $ V3: int  1 2 3