[R] about combining two dataframes

[Ulrik Stervbo]

Hi Lily,

maybe you should read up on what bind_rows/bind_cols (or the base functions
rbind and cbind) do.

bind_cols and cbind will fail in this case because of the different number
of rows.

bind_rows and rbind will fail because the column names are different - how
can R know that month and mon really is the same.

Depending on what you want, you should unify the column names (I have a
hunch that this is what you want), or make sure the data.frames have the
same number of rows.

HTH
Ulrik



On Wed, 24 May 2017 at 19:30 lily li <chocold12 at gmail.com> wrote:

> Hi all,
>
> I have a question about combining two data frames. For example, there are
> the two dataframes below, with the same structure but different column
> names and column lengths. How to add the values in DF2 to the end of DF1,
> though the column names do not match? How to add more than two? Thanks.
>
> DF1
> year   month   day   product1   product2   product3
> 1981     1          1         18              56            20
> 1981     1          2         19              45            22
> 1981     1          3         16              48            28
> 1981     1          4         19              50            21
>
> DF2
> yr         mon      d         prod        prod2       prod3
> 1981     2          1         17              49            25
> 1981     2          2         20              47            23
> 1981     2          3         21              52            27
>
> I use the code below but it does not work.
> require(dplyr)
> bind_rows(DF1, DF2) or bind_cols(DF1, DF2)
>
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>
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