Changing list data to include a new column

[Sunhwa Hagiwara]

Hi, I asked this question in Cross Validated but they requested I move it here,

I have a dataset of the form:

YEAR ID Data
year X 1 x_1
year X 2 x_2
year Y 1 y_1
year Y 2 y_2
...

I would like to put it in the form:

YEAR ID Data_X Data_Y
year 1 x_1 y_1
year 2 x_2 y_2
...

I feel like we want to make vectors somehow out of the years $X$ and $Y$, so that here the data set becomes a $2 \times 1$ vector, then take the transpose of it.

A comment as an answer there said to use "dcast" in R, is there any equivalent command for this in Stata?

[Nick Cox]

Sorry, no idea what dcast does in R.

Concrete examples beat schematic examples. We give concrete advice on that in http://www.statalist.org/forums/help#stata -- which you were asked to read before posting.

Your data imply four variables (not three), say. With some guesswork I am led to suggest the following example:

clear
input YEAR str1 ID1 ID2 Data
2014 X 1 12
2015 X 2 34
2014 Y 1 56
2015 Y 2 78
end
reshape wide Data , i(YEAR ID2) j(ID1) string
list


     +----------------------------+
     | YEAR   ID2   DataX   DataY |
     |----------------------------|
  1. | 2014     1      12      56 |
  2. | 2015     2      34      78 |
     +----------------------------+

.

Very possibly your example was intended to refer to just one year, and the same code should work for that.

[Sunhwa Hagiwara]

Hi, thank you very much, I've read the beginning guide now and will use concrete examples in the future.