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# st: RE: work with larger string length

 From Nick Cox To "'statalist@hsphsun2.harvard.edu'" Subject st: RE: work with larger string length Date Tue, 27 Mar 2012 17:14:23 +0100

```First taking your questions one by one:

1. since string limit is 244, what is it about extended function subinstr that makes string limitation non issue. Does extended function increase the acceptable string length which I think is unlikely?

I don't know what kind of answer you expect here, but the short answer is yes. It is a fact that using -subinstr()- rather than -: subinstr- bites as the limit on the length of strings in string expressions is 244 in all current flavours of Stata. See -help on limits-. I can't expand on why Stata is written this way; that's an interesting question to me too.

2. looks like the same question to me.

3. when I use length command to find the length of the string in stata12, I get unrecognized command. Any idea.

Works for me. I can't say what you did wrong, as you don't show any example code.

. di length("frog")
4

Now I want to comment on your code

foreach x of  varlist hits* {
gen temp=`x'
replace  `x'=.
egen tot_`x'=rowtotal(hits*)
replace `x'=temp
drop temp
}

A better solution (in my view) is implied by advice given earlier in the thread you started previously.

unab hitlist : hits*
foreach x of local hitlist {
local thislist : list hitlist - x
egen tot_`x' = rowtotal(`thislist')
}

Nick
n.j.cox@durham.ac.uk

tashi lama

I posted a question related to this earlier and received favorable answers although I am not sure if I completely understand the science. I have dared to post this question again. Any help will be highly appreciated.

I have a dataset of some 48 variables and the nature of my problem obliges me to have all variables start with hit. when I ran this code,

foreach x of varlist hit* {
local varlist_new=subinstr("`varlist'", "`x'","",1)
di "`varlist_new'"
egen tot_`x'=rowtotal(`varlist_new')
}

The problem was I did get answers but the upon close analysis, the answers were incorrect. I am assuming it must be because the length of my string variables exceed 244. Now, I was advised to use extended subinstr function, which seem to work. Further I wrote a code below, which also works.

foreach x of  varlist hits* {
gen temp=`x'
replace  `x'=.
egen tot_`x'=rowtotal(hits*)
replace `x'=temp
drop temp
}

My question is

1. since string limit is 244, what is it about extended function subinstr that makes string limitation non issue. Does extended function increase the acceptable string length which I think is unlikely?

2. The code without subinstr works and again, it sounds like string limitation is a non issue. Again, is the code increasing the accepateble length of the string??

3. when I use length command to find the length of the string in stata12, I get unrecognized command. Any idea.

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```