Data manipulation question

[Willem Vanlaer]

Hey,

I have a small question with regard to some data I am analyzing.
They are in the form of:

x	y
0,2	4	6	7
0,3	2	5	6	9	10
0,4	3	2	12	4

So for x = 0,2, I have 4 observations for y: 4,6 and 7.
I would like to get them like this:

x	y
0,2	4
0,2	6
0,2	7
0,3	2
0,3	5
0,3	6
..	..

Is there a easy way to do this in Stata?

Thanks,

Willem

[Clyde Schechter]

Yes, Stata excels at this! See the -reshape- command.

[David Poensgen]

Lets assume the other variables (in Stata each "column" represents a variable) are called y2, y3 etc., you could use stack:

stack x y x y2 x y3 x y4 ... , into (x y)

sort x
And then, to get rid of the cases where y# was missing:

drop if y==.

This assumes that it is feasible to list all variables by hand in the stack command; if there's too many, I guess the varlist for the stack command can be created by a loop.

[Willem Vanlaer]

Lets assume the other variables (in Stata each "column" represents a variable) are called y2, y3 etc., you could use stack:

stack x y x y2 x y3 x y4 ... , into (x y)

sort x
And then, to get rid of the cases where y# was missing:

drop if y==.

This assumes that it is feasible to list all variables by hand in the stack command; if there's too many, I guess the varlist for the stack command can be created by a loop.

I have max 30 "y-variables", so this should be feasible.

[Willem Vanlaer]

Yes, Stata excels at this! See the -reshape- command.

I'll have a look at this first and see whether this is easier than the solution proposed above.

Thanks for the feedback, both!