[R] Data.frame of Different Length

[Jeff Newmiller]

There are many ways to combine data frames, but the method you have chosen is extremely rare because you do not appear to be creating sensible relationships in the rows of the data frame, so your final result seems unlikely to be understandable by normal interpretation of tabular data. See ?merge for more normal ways to combine data frames.

However, with respect to your questions:

1) The usual way to remove a column is to use negative integer indexing:
a <- a[ , -2 ]

2) To add more columns, just do it again with the answer you have. I do think you are taking an over-complicated approach:

n <- max( nrow(d1), nrow(d2), nrow(d3))
ix <- seq.int( n )
a <- data.frame( d1_date=d1$date[ix], d2_date=d2$date[ix], d3_date=d3$date[ix] )

On September 17, 2018 12:17:03 AM PDT, Ogbos Okike <giftedlife2014 using gmail.com> wrote:
>Dear Contributors,
>
>I have two data frame of different column lengths. I am trying to have
>them
>in one data frame.
>Using
>A<-d1$date
>B<-d2$date
>a<-data.table(A )[ , I := .I][data.table(B )[ , I := .I], on = "I"]
>I got
>1: 2005-01-04  1 2005-01-04
> 2: 2005-01-19  2 2005-01-19
> 3: 2005-01-22  3 2005-01-22
> 4: 2005-02-24  4 2005-02-19
> 5: 2005-05-09  5 2005-02-24
> 6: 2005-05-16  6 2005-05-09
> 7: 2005-06-17  7 2005-05-11
> 8: 2005-07-17  8 2005-05-16
> 9: 2005-08-07  9 2005-06-13
>10: 2005-09-11 10 2005-06-17
>11: 2005-09-13 11 2005-06-22
>12: 2005-09-15 12 2005-07-18
>13:         NA 13 2005-08-03
>14:         NA 14 2005-08-07
>15:         NA 15 2005-08-10
>16:         NA 16 2005-08-25
>17:         NA 17 2005-09-13
>18:         NA 18 2005-09-15
>19:         NA 19 2005-10-13
>20:         NA 20 2005-12-15
>which is fine.
>
>I have two more problems:
>1) how to remove the nos 1 to 20 inserted at the middle of the dates.
>
>2) how to include more columns.
>
>I have about 5 columns of different lengths which I wish to have in one
>data frame.
>
>I will remain grateful if assisted.
>
>Best regards
>Ogbos
>
>	[[alternative HTML version deleted]]
>
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-- 
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