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Dplyr 0.3 cannot embed data.table?

I have loaded the following settings and dplyr (0.3) and data.table (1.9.3).

R version 3.1.1 (2014-07-10)
Platform: x86_64-apple-darwin10.8.0 (64-bit)

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] data.table_1.9.3 dplyr_0.3       

loaded via a namespace (and not attached):
[1] assertthat_0.1 DBI_0.3.1      magrittr_1.0.1 parallel_3.1.1 plyr_1.8.1     Rcpp_0.11.2   
[7] reshape2_1.4   stringr_0.6.2  tools_3.1.1

Here is the dataset. 2 data.tables and 2 data.frames. These two sets have the same content.

DT_1 = data.table(x = rep(c("a","b","c"), each = 3), y = c(1,3,6), v = 1:9)
DT_2 = data.table(V1 = c("b","c"),foo = c(4,2))

DT_1_df = data.frame(x = rep(c("a","b","c"), each = 3), y = c(1,3,6), v = 1:9)
DT_2_df = data.frame(V1 = c("b","c"),foo = c(4,2))

data.table way

When an inner join is performed on two data tables using the data.table method, we get the following result:

setkey(DT_1, x); setkey(DT_2, V1)
DT_1[DT_2]
  x y v foo
1: b 1 4   4
2: b 3 5   4
3: b 6 6   4
4: c 1 7   2
5: c 3 8   2
6: c 6 9   2

dplyr0.3 inner_join on data.tables

It gives an error when using inner_join dplyr on two data tables:

inner_join(DT_1, DT_2, by=("x"="V1"))
Error in setkeyv(x, by$x) : some columns are not in the data.table: V1

dplyr0.3 inner_join on data.frame and data.table

Another error if working with data with a data framework:

inner_join(DT_1, DT_2_df, by = c("x" = "V1"))
Error: Data table joins must be on same key

dplyr0.3 inner_join on data.frames

inner_join, however, works great on dataframes:

inner_join(DT_1_df, DT_2_df, by = c("x" = "V1"))
  x y v foo
1 b 1 4   4
2 b 3 5   4
3 b 6 6   4
4 c 1 7   2
5 c 3 8   2
6 c 6 9   2

Can anyone explain why this is happening?

+4
1

, .

https://github.com/hadley/dplyr , dplyr "join" . : " , ". , , :

library(dplyr); library(data.table)
DT_1 = data.table(x=rep(c("a","b","c"),each=3), y=c(1,3,6), v=1:9)
DT_2 = data.table(V1=c("b","c"),foo=c(4,2)) # note the variable name assigned to first column
DT_2b = data.table(x=c("b","c"),foo=c(4,2)) # note the variable name assigned to first column

inner_join(DT_1, DT_2b, by= "x")
Source: local data table [6 x 4]
  x y v foo
1 b 1 4   4
2 b 3 5   4
3 b 6 6   4
4 c 1 7   2
5 c 3 8   2
6 c 6 9   2

inner_join(DT_1, DT_2, by = c("x" = "V1"))
Error: Data table joins must be on same key
+1

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