Generating Gini Coefficient (Using ineqdeco Command) as a Variable by Group

[Ryan Kim]

Dear Statalist,

I recently learned that one of the ways to generate Gini Coefficient is to use ineqdeco command.
I wanted to directly include the derived Gini coefficient value as a variable such as below.

* Example generated by -dataex-. To install: ssc install dataex
clear
input float(group id income)
1 1      0
1 2   5000
1 3  12000
1 4  18000
2 5  30000
2 6  40000
2 7  60000
3 8 100000
3 9 150000
end

Using the above example data set, if I run the below code, I create a variable "gini_for_all" which includes the derived Gini coefficient from all the id(s) based on their income values.

ineqdeco income
gen gini_for_all=r(gini)

But I am trying to take one step further; what I want to do is I want to generate Gini coefficient that is calculated for each group and include each within "gini_for_group" variable.
I thought "by group" or "bysort group" were going to work but the error message returned me "ineqdeco may not be combined with by".
Is there a clever way to address this?
Thank you.

[Øyvind Snilsberg]

ineqdeco income, by(group)

[Ryan Kim]

Thank you for the prompt reply!
I should have carefully looked at the manual.

May I also ask how I can assign the three different Gini coefficient values for each sub-group in a newly created variable?
I found that

r(gini_k)

returns the Gini value for each subgroup k but

display r(gini_k)

actually returns nothing.

->updated question:
I knew that I should type in these separately.

display r(gini_1)
display r(gini_2)
display r(gini_3)

Is there a way to return these at once in the command?

[Øyvind Snilsberg]

perhaps,

display r(gini_1) _skip(5) r(gini_2) _skip(5) r(gini_3)

or,

mat m = r(gini_1) \ r(gini_2) \ r(gini_3)
mat list m