Also check out -tokenize- and a discussion in

SJ-3-2 pr0009 . . . . . . . . . . . . . Speaking Stata: Problems with lists

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . N. J. Cox

Q2/03 SJ 3(2):185--202 (no commands)

discusses ways of working through lists held in macros

Nick

[hidden email]
Sergiy Radyakin

I salute your intent to use arrays for that: indeed you can do it with

arrays. Many statalisters

prefer variable lists instead. Given that you want only one var from

each list, just extract it

as a word by its index. See below.

If you are doing any data mining/optimal model search, investigate

further, e.g. see -bestreg-

by Zurab Sajaia:

net from

http://adeptanalytics.org/download/ado/sysuse auto

local depvars "price weight length"

local controlvars "rep78 foreign mpg"

local n_models : word count `depvars'

assert `n_models'==`:word count `controlvars'' // this ensures that

the two lists are of the same length

forval i=1/`n_models' {

local this_depvar `: word `i' of `depvars''

local this_controlvar `:word `i' of `controlvars''

regress `this_depvar' `this_controlvar'

}

On Thu, Dec 2, 2010 at 4:03 PM, miros lav

> I am wondering whether it is possible to reference the individual

> elements of a (local) macro by a number. For example, if I have the

> local macro x "var1 var2 var3". How would something like reg y `x'[3]

> work.

>

> Long explanation:

>

> I would like to estimate a number of models with different dependent

> and independent variables. The control variable varies with the

> dependent variable. I would like to use some kind of loop structure

> (since I want to do a lot of estimations). so, I have defined two

> macros. Lets say that they each have three elements.

>

> local depvars " depvar1 depvar2 depvar3"

> local controlvars " controlvar1 controlvar2 controlvar3"

>

> I would like to do something like that

>

> i=1

> foreach c of local depvar{

> reg `c' `controlvars'[i]

> i++

> }

>

> Thanks for your help!

*

* For searches and help try:

*

http://www.stata.com/help.cgi?search*

http://www.stata.com/support/statalist/faq*

http://www.ats.ucla.edu/stat/stata/