Can't convert yymmdd to mmddyy

Question

Here mydata

ga=structure(list(Date = c(190410L, 190410L, 190410L, 190410L, 190410L
), open = c(162.4, 162.57, 162.94, 162.87, 162.96), high = c(162.57, 
162.94, 162.95, 163, 163.11), low = c(162.12, 162.51, 162.83, 
162.83, 162.95), close = c(162.57, 162.94, 162.9, 162.95, 162.95
)), class = "data.frame", row.names = c(NA, -5L))

I use mdy function from lubridate

ga$Date=mdy(ga$Date)

So I get only NA. How can i get such output format(mm.dd.yy)

    Date        open   high    low  close
1   04.10.2019 162.40 162.57 162.12 162.57
2   04.10.2019 162.57 162.94 162.51 162.94
3   04.10.2019 162.94 162.95 162.83 162.90
4   04.10.2019162.87 163.00 162.83 162.95
5   04.10.2019 162.96 163.11 162.95 162.95

Do you need this? `lubridate::ymd(ga$Date)`? – NelsonGon Jun 29 '19 at 14:20 — NelsonGon, Jun 29 '19 at 14:20

NelsonGon · Answer 1 · 2019-06-29T14:39:36.383

We can use:

strftime(lubridate::ymd(ga$Date),"%m %d %Y")
[1] "04 10 2019" "04 10 2019" "04 10 2019" "04 10 2019" "04 10 2019"

The above will return a character representation of the date, if you want to keep as date(I find the display somewhat misleading), you could use:

lubridate::mdy(strftime(lubridate::ymd(ga$Date),"%m %d %y"))
[1] "2019-04-10" "2019-04-10" "2019-04-10" "2019-04-10" "2019-04-10"

Perhaps mdy defaults to this kind of representation as shown here.

score 3 · Accepted Answer · answered Jun 29 '19 at 14:24

3

We can use base R to get output in required format

ga$Date <- format(as.Date(as.character(ga$Date), "%y%m%d"), "%m.%d.%Y")

ga
#        Date   open   high    low  close
#1 04.10.2019 162.40 162.57 162.12 162.57
#2 04.10.2019 162.57 162.94 162.51 162.94
#3 04.10.2019 162.94 162.95 162.83 162.90
#4 04.10.2019 162.87 163.00 162.83 162.95
#5 04.10.2019 162.96 163.11 162.95 162.95

answered Jun 29 '19 at 14:24

Ronak Shah

377,200
20
156
213

may i ask you, how to aggaregate variable (open high low close) by date by sum? – psysky Jun 29 '19 at 14:39
1

@G-spot `aggregate` by group? `aggregate(.~Date, ga, sum)`. – Ronak Shah Jun 29 '19 at 14:41

akrun · Answer 3 · 2019-06-29T20:57:52.190

3

We can use anydate from anytime

library(anytime)
format(anydate(as.character(ga$Date)), "%m.%d.%Y")
#[1] "04.10.2019" "04.10.2019" "04.10.2019" "04.10.2019" "04.10.2019"

If we want to convert a date time format

str1 <- "190410;100000"
format(as.POSIXct(str1, format= "%y%m%d;%H%M%S"), "%m.%d.%Y %H:%M")
#[1] "04.10.2019 10:00"

edited Jun 29 '19 at 20:57

answered Jun 29 '19 at 17:17

akrun

874,273
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Can't convert yymmdd to mmddyy

3 Answers3