Typo time:
If you had
local a "`a' `i'"
local -a- would be born as " 1"
Nick
[email protected]
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]]On Behalf Of n j cox
> Sent: 30 May 2007 17:14
> To: [email protected]
> Subject: Re: st: RE: new local macro from results of loop
>
>
> The principle is shown by a simpler loop:
>
> forval i = 1/10 {
> local a `a' `i'
> }
>
> We assume that -local a- has not been defined upstream of this.
>
> First time round the loop, Stata sees, initially,
>
> local a `a' `i'
>
> and first substitutes macro definitions it already knows. -a-
> as just assumed doesn't exist, or equivalently it is replaced
> by an empty string. -i- is "1", as far as Stata knows, so after
> substitution Stata sees
>
> local a 1
>
> This is now an assignment. -local a- is assigned whatever follows
> it. So -a- is born as "1".
>
> Second time round the loop, Stata sees, after substitution
>
> local a 1 2
>
> and so forth. So -local a- accumulates the changing values of -i-.
>
> A mantra: substitution of macro definitions precedes evaluation of
> expressions.
>
> The double quotes are optional, for most purposes.
>
> If you had
>
> local "`a' `i'"
>
> local -a- would be borm as " 1"
>
> and if you had
>
> local a "`a'`i' "
>
> it would be born as "1 ", and so on. Mostly, but not always, these
> extra spaces disappear in the wash.
>
> Similarly, an equals sign is optional, for this problem and for yours.
>
> There is a tutorial covering this in your context at
>
> Cox, N.J. 2002. How to face lists with fortitude. Stata Journal
> 2(2):202--222
>
> demonstrates the usefulness of for, foreach, forvalues, and
> local macros for interactive (non programming) tasks
>
> Earlier versions of that are accessible at
> http://fmwww.bc.edu/RePEc/usug2002/fortitude.pdf
> http://www.cpc.unc.edu/services/computer/presentations/statatu
torial/cox_article.pdf
and it's all in the manual somewhere.
Nick
[email protected]
Ronnie Babigumira
Both of your suggestions work (they look the same save for the "" in
Maartens solution). That said, I have missed the
obvious so I will ask that you help me with the logic
My part of the loop goes through each element and does my stuff
foreach v of local lvstk {
--my stuff--
How exactly does your part work
local lvstknos "`lvstknos' `v'nbeg `v'nend"
local new `new' `v'nbeg `v'nend
It appears that you are each amending a new local (part of my confusion
is that this new local has not been initialised
before). My other problem is that I don't see the part that instructs
Stata to incrementally build the new local
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
