How to resolve xtine _ 'too few variables specified' error

[Sri Kruthi]

I have a data with more than 1million rows, and I have no issues with running xtset command, but I have having this error with xtline _ 'too few variables specified'. Can someone please help me with this?

[Andrew Musau]

The syntax for xtline is

Syntax

Graph by panel

xtline varlist [if] [in] [, panel_options]


Overlaid panels

xtline varname [if] [in], overlay [overlaid_options]

So you need to specify a variable if overlaying plots or one or more variables if graphing by panel. In a sense, what do you want to plot?

[Sri Kruthi]

The below mentioned is my code:

xtset school1 school_year
xtline drugandalcoholuse_mean, tlabel

The results of xtset are
(
Panel variable: school1 (weakly balanced)
Time variable: school_year, 2008 to 2021
Delta: 1 unit
)

Where as for xltine I am getting "too few variables specified" error.
Am I missing something in this?

[Sri Kruthi]

Thankyou for the reply. The below mentioned is my code:

xtset school1 school_year
xtline drugandalcoholuse_mean, tlabel

The results of xtset are
(
Panel variable: school1 (weakly balanced)
Time variable: school_year, 2008 to 2021
Delta: 1 unit
)

Where as for xltine I am getting "too few variables specified" error.
Am I missing something in this?

[Andrew Musau]

xtset school1 school_year
xtline drugandalcoholuse_mean, tlabel

The 1 million+ observations over a period of 14 years represent over 71,000 panels - so I do not see any scope to create such a graph. But you can start at:

xtset school1 school_year
sort school1 school_year
xtline drugandalcoholuse_mean in 1/140

If this results in an error, provide a reproducible example, e.g., by copying and pasting the result of the following:

dataex school1 school_year drugandalcoholuse_mean

[Sri Kruthi]

Thankyou so much for the reply!

[Andrew Musau]

I should add to #5 that you can plot the averaged drug and alcohol use in the sample. This will be across all panels.

preserve
collapse drugandalcoholuse_mean, by(school_year)
set scheme s1mono
tw line drugandalcoholuse_mean school_year, sort xtitle("") ytitle(Mean Drug and Alcohol Use)
restore

[Sri Kruthi]

Thank you for #7 plot. I have already plotted a similar graph. But as for 'xtset', I am getting an error. It says 'repeated time values within panel'. Can you please help me with this as well?

[Andrew Musau]

That is indicative of duplicate observations. To xtset, you need school-level panel data, i.e., at most one observation of a school in a given school year. Perhaps you have student-level data. In any case, once you understand the structure of your data, you can still enforce a school-level panel by collapsing the data if the aggregation is at a lower level. Whether you sum or take the mean depends on what makes the most sense to you.

collapse drugandalcoholuse_mean, by(school1 school_year)
xtset school1 school_year

or

collapse (sum) drugandalcoholuse_tot= drugandalcoholuse_mean, by(school1 school_year)
xtset school1 school_year

[Sri Kruthi]

It worked. Thank you so much. But can I not use "xtline drugandalcoholuse_mean, overlay legend(off)"? It is giving me error of "too many sersets". What could be the possible reason?

[Andrew Musau]

What I said in #5. With overlaid lines, you are already struggling with \(N= 10\) panels. So it is not reasonable to expect that you will produce any meaningful graph with a large number of panels.

[Sri Kruthi]

Got it. Thank you so much !