Formatting dates using a condition












0















I am using "R" to format a character variable that has two different kinds of date formats (MM-DD-YYYY & YYYY-MM-DD). The second is an excel origin date.



DateVar <- c("12-07-2017", "43229", "43137", "03-27-2018")


I created vector using grepl to identify both types and then a for loop to apply the as.date function to only the "excel origin dates".



indicator <- !grepl("-", DateVar)

for(i in indicator == TRUE){
as.date(DateVar, origin = "1899-12-30")


It is not working for me however, so I am looking if someone can point me in the right direction.



Thanks.










share|improve this question



























    0















    I am using "R" to format a character variable that has two different kinds of date formats (MM-DD-YYYY & YYYY-MM-DD). The second is an excel origin date.



    DateVar <- c("12-07-2017", "43229", "43137", "03-27-2018")


    I created vector using grepl to identify both types and then a for loop to apply the as.date function to only the "excel origin dates".



    indicator <- !grepl("-", DateVar)

    for(i in indicator == TRUE){
    as.date(DateVar, origin = "1899-12-30")


    It is not working for me however, so I am looking if someone can point me in the right direction.



    Thanks.










    share|improve this question

























      0












      0








      0








      I am using "R" to format a character variable that has two different kinds of date formats (MM-DD-YYYY & YYYY-MM-DD). The second is an excel origin date.



      DateVar <- c("12-07-2017", "43229", "43137", "03-27-2018")


      I created vector using grepl to identify both types and then a for loop to apply the as.date function to only the "excel origin dates".



      indicator <- !grepl("-", DateVar)

      for(i in indicator == TRUE){
      as.date(DateVar, origin = "1899-12-30")


      It is not working for me however, so I am looking if someone can point me in the right direction.



      Thanks.










      share|improve this question














      I am using "R" to format a character variable that has two different kinds of date formats (MM-DD-YYYY & YYYY-MM-DD). The second is an excel origin date.



      DateVar <- c("12-07-2017", "43229", "43137", "03-27-2018")


      I created vector using grepl to identify both types and then a for loop to apply the as.date function to only the "excel origin dates".



      indicator <- !grepl("-", DateVar)

      for(i in indicator == TRUE){
      as.date(DateVar, origin = "1899-12-30")


      It is not working for me however, so I am looking if someone can point me in the right direction.



      Thanks.







      r loops date






      share|improve this question













      share|improve this question











      share|improve this question




      share|improve this question










      asked Nov 19 '18 at 13:11









      SteveMSteveM

      224




      224
























          1 Answer
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          Couple of things: The for loop is unnecessary - just subset DateVar with [indicator]. Second, it's as.Date, not as.date (note the "D"). Third, since it's a character vector, you need to pass the origin numbers through as.integer for as.Date to be able to work with them:



          as.Date(as.integer(DateVar[indicator]), origin = "1899-12-30")


          (or, without the intervening indicator assignment:



          as.Date(as.integer(DateVar[!grepl("-",DateVar)]), origin = "1899-12-30")

          [1] "2018-05-09" "2018-02-06"


          If you wish to input these dates back into DateVar, you again use the subset function:



          DateVar[indicator]<-format(as.Date(as.integer(DateVar[indicator]), origin = "1899-12-30"), "%m-%d-%Y")





          share|improve this answer


























          • Thank you for your detailed reply as I am fairly new to "R". This appears to work for my case, however my followup question would be "How can I apply to this my existing variable?". I tried to use dplyr::mutate and apply the as.Date function you provided above but I get an error message.

            – SteveM
            Nov 19 '18 at 14:07











          • You want to change DateVar so that the origin dates become class Date?

            – iod
            Nov 19 '18 at 14:10











          • Yes - or alternatively change the other date format be be YYYY-MM-DD since that is the format the excel origin dates are in. I just want to have a consistent date format for my DateVar variable.

            – SteveM
            Nov 19 '18 at 14:18











          • Added code above.

            – iod
            Nov 19 '18 at 14:19











          • This worked beautifully. Thanks so much!

            – SteveM
            Nov 19 '18 at 14:40











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          1 Answer
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          active

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          1 Answer
          1






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes









          1














          Couple of things: The for loop is unnecessary - just subset DateVar with [indicator]. Second, it's as.Date, not as.date (note the "D"). Third, since it's a character vector, you need to pass the origin numbers through as.integer for as.Date to be able to work with them:



          as.Date(as.integer(DateVar[indicator]), origin = "1899-12-30")


          (or, without the intervening indicator assignment:



          as.Date(as.integer(DateVar[!grepl("-",DateVar)]), origin = "1899-12-30")

          [1] "2018-05-09" "2018-02-06"


          If you wish to input these dates back into DateVar, you again use the subset function:



          DateVar[indicator]<-format(as.Date(as.integer(DateVar[indicator]), origin = "1899-12-30"), "%m-%d-%Y")





          share|improve this answer


























          • Thank you for your detailed reply as I am fairly new to "R". This appears to work for my case, however my followup question would be "How can I apply to this my existing variable?". I tried to use dplyr::mutate and apply the as.Date function you provided above but I get an error message.

            – SteveM
            Nov 19 '18 at 14:07











          • You want to change DateVar so that the origin dates become class Date?

            – iod
            Nov 19 '18 at 14:10











          • Yes - or alternatively change the other date format be be YYYY-MM-DD since that is the format the excel origin dates are in. I just want to have a consistent date format for my DateVar variable.

            – SteveM
            Nov 19 '18 at 14:18











          • Added code above.

            – iod
            Nov 19 '18 at 14:19











          • This worked beautifully. Thanks so much!

            – SteveM
            Nov 19 '18 at 14:40
















          1














          Couple of things: The for loop is unnecessary - just subset DateVar with [indicator]. Second, it's as.Date, not as.date (note the "D"). Third, since it's a character vector, you need to pass the origin numbers through as.integer for as.Date to be able to work with them:



          as.Date(as.integer(DateVar[indicator]), origin = "1899-12-30")


          (or, without the intervening indicator assignment:



          as.Date(as.integer(DateVar[!grepl("-",DateVar)]), origin = "1899-12-30")

          [1] "2018-05-09" "2018-02-06"


          If you wish to input these dates back into DateVar, you again use the subset function:



          DateVar[indicator]<-format(as.Date(as.integer(DateVar[indicator]), origin = "1899-12-30"), "%m-%d-%Y")





          share|improve this answer


























          • Thank you for your detailed reply as I am fairly new to "R". This appears to work for my case, however my followup question would be "How can I apply to this my existing variable?". I tried to use dplyr::mutate and apply the as.Date function you provided above but I get an error message.

            – SteveM
            Nov 19 '18 at 14:07











          • You want to change DateVar so that the origin dates become class Date?

            – iod
            Nov 19 '18 at 14:10











          • Yes - or alternatively change the other date format be be YYYY-MM-DD since that is the format the excel origin dates are in. I just want to have a consistent date format for my DateVar variable.

            – SteveM
            Nov 19 '18 at 14:18











          • Added code above.

            – iod
            Nov 19 '18 at 14:19











          • This worked beautifully. Thanks so much!

            – SteveM
            Nov 19 '18 at 14:40














          1












          1








          1







          Couple of things: The for loop is unnecessary - just subset DateVar with [indicator]. Second, it's as.Date, not as.date (note the "D"). Third, since it's a character vector, you need to pass the origin numbers through as.integer for as.Date to be able to work with them:



          as.Date(as.integer(DateVar[indicator]), origin = "1899-12-30")


          (or, without the intervening indicator assignment:



          as.Date(as.integer(DateVar[!grepl("-",DateVar)]), origin = "1899-12-30")

          [1] "2018-05-09" "2018-02-06"


          If you wish to input these dates back into DateVar, you again use the subset function:



          DateVar[indicator]<-format(as.Date(as.integer(DateVar[indicator]), origin = "1899-12-30"), "%m-%d-%Y")





          share|improve this answer















          Couple of things: The for loop is unnecessary - just subset DateVar with [indicator]. Second, it's as.Date, not as.date (note the "D"). Third, since it's a character vector, you need to pass the origin numbers through as.integer for as.Date to be able to work with them:



          as.Date(as.integer(DateVar[indicator]), origin = "1899-12-30")


          (or, without the intervening indicator assignment:



          as.Date(as.integer(DateVar[!grepl("-",DateVar)]), origin = "1899-12-30")

          [1] "2018-05-09" "2018-02-06"


          If you wish to input these dates back into DateVar, you again use the subset function:



          DateVar[indicator]<-format(as.Date(as.integer(DateVar[indicator]), origin = "1899-12-30"), "%m-%d-%Y")






          share|improve this answer














          share|improve this answer



          share|improve this answer








          edited Nov 19 '18 at 20:45

























          answered Nov 19 '18 at 13:23









          iodiod

          3,8432722




          3,8432722













          • Thank you for your detailed reply as I am fairly new to "R". This appears to work for my case, however my followup question would be "How can I apply to this my existing variable?". I tried to use dplyr::mutate and apply the as.Date function you provided above but I get an error message.

            – SteveM
            Nov 19 '18 at 14:07











          • You want to change DateVar so that the origin dates become class Date?

            – iod
            Nov 19 '18 at 14:10











          • Yes - or alternatively change the other date format be be YYYY-MM-DD since that is the format the excel origin dates are in. I just want to have a consistent date format for my DateVar variable.

            – SteveM
            Nov 19 '18 at 14:18











          • Added code above.

            – iod
            Nov 19 '18 at 14:19











          • This worked beautifully. Thanks so much!

            – SteveM
            Nov 19 '18 at 14:40



















          • Thank you for your detailed reply as I am fairly new to "R". This appears to work for my case, however my followup question would be "How can I apply to this my existing variable?". I tried to use dplyr::mutate and apply the as.Date function you provided above but I get an error message.

            – SteveM
            Nov 19 '18 at 14:07











          • You want to change DateVar so that the origin dates become class Date?

            – iod
            Nov 19 '18 at 14:10











          • Yes - or alternatively change the other date format be be YYYY-MM-DD since that is the format the excel origin dates are in. I just want to have a consistent date format for my DateVar variable.

            – SteveM
            Nov 19 '18 at 14:18











          • Added code above.

            – iod
            Nov 19 '18 at 14:19











          • This worked beautifully. Thanks so much!

            – SteveM
            Nov 19 '18 at 14:40

















          Thank you for your detailed reply as I am fairly new to "R". This appears to work for my case, however my followup question would be "How can I apply to this my existing variable?". I tried to use dplyr::mutate and apply the as.Date function you provided above but I get an error message.

          – SteveM
          Nov 19 '18 at 14:07





          Thank you for your detailed reply as I am fairly new to "R". This appears to work for my case, however my followup question would be "How can I apply to this my existing variable?". I tried to use dplyr::mutate and apply the as.Date function you provided above but I get an error message.

          – SteveM
          Nov 19 '18 at 14:07













          You want to change DateVar so that the origin dates become class Date?

          – iod
          Nov 19 '18 at 14:10





          You want to change DateVar so that the origin dates become class Date?

          – iod
          Nov 19 '18 at 14:10













          Yes - or alternatively change the other date format be be YYYY-MM-DD since that is the format the excel origin dates are in. I just want to have a consistent date format for my DateVar variable.

          – SteveM
          Nov 19 '18 at 14:18





          Yes - or alternatively change the other date format be be YYYY-MM-DD since that is the format the excel origin dates are in. I just want to have a consistent date format for my DateVar variable.

          – SteveM
          Nov 19 '18 at 14:18













          Added code above.

          – iod
          Nov 19 '18 at 14:19





          Added code above.

          – iod
          Nov 19 '18 at 14:19













          This worked beautifully. Thanks so much!

          – SteveM
          Nov 19 '18 at 14:40





          This worked beautifully. Thanks so much!

          – SteveM
          Nov 19 '18 at 14:40




















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