Two line of the same graph in stata

[dupont john]

Hi there

I did the following two graph and I was wondering if there was a command that could enable me to have these two line on the same graph?

preserve
keep if  X==1
twoway (line Y year)
restore

preserve
keep if  X==0
twoway (line Y year)
restore

Thanks a lot!

Best,

JD

[Alan Neustadtl]

How about something like this:

twoway (line Y year if X==1) (​(line Y year if X==0)

Best,
Alan

[dupont john]

Hi Alan

Thanks for your reply
This command doesn't work as I actually do:

 preserve
keep if  X==1
collapse (mean) Y, by(year)
twoway (line Y year)
restore  

preserve
keep if  X==0
collapse (mean) Y , by(year)
twoway (line Y year)
restore

Hence
twoway (line Y year if X==1) ((line Y year if X==0) doesn't work.



Is there another way of doing it?


Thanks a lot!


Best Regards,


JD

[Nick Cox]

Don't do that then!

preserve
keep if  X==1 | X == 0  
collapse (mean) Y, by(year X)
twoway (line Y year if X==1) (​(line Y year if X==0)
restore