Problem replicating a seed

[Santiago Reyes]

Hi all,

I am having a problem that might be just a mistake on understading how set seet works in the new Stata 14. I needed to select randomly three evaluations and create an average score per project so in my do file I set a seed, create a random number and selected the three evaluations with the largest random numbers per project. However when I run the do file, each time I get a different result. Why does that happen if each time the do file runs the seed is set at the same number?

The do file is the following:

clear all
set more off

set seed 988

gen random=runiform()
by iddelemprendimiento: egen r1=max(random)
gen ev1=1 if random==r1
by iddelemprendimiento: egen r2=max(random) if ev1==.
gen ev2=1 if random==r2
by iddelemprendimiento: egen r3=max(random) if (ev1==. & ev2==.)
gen ev3=1 if random==r3
gen evaluaciones=1 if ev1==1 | ev2==1 | ev3==1

collapse (mean) score if evaluaciones==1, by(iddelemprendimiento)

[Carlo Lazzaro]

Santiago:
welcome to the list.
Using a limited part of your code (by the way, you probably forgot to paste the number of observations -set-), I cannot replicate the reported -seed- problem:

. clear all

.  set more off

.  set seed 988

. set obs 10
number of observations (_N) was 0, now 10

.  gen random=runiform()

. su

    Variable |        Obs        Mean    Std. Dev.       Min        Max
-------------+---------------------------------------------------------
      random |         10    .5739065    .3332505   .0470875   .9869751

. drop _all

. clear all

.  set more off

.  set seed 988

. set obs 10
number of observations (_N) was 0, now 10

.  gen random=runiform()

. su

    Variable |        Obs        Mean    Std. Dev.       Min        Max
-------------+---------------------------------------------------------
      random |         10    .5739065    .3332505   .0470875   .9869751

[Santiago Reyes]

Thanks Carlo for the reply.

I have 1,567 observations. I am also attaching the ranking the first time I run the do file and the ranking when I run it for the second time. As you can see, the order changes and I do not know why

[Carlo Lazzaro]

Santiago:
-as per FAQ, posting screenshots id pointless, as tehy are difficult to read and impossible to comment on; please, use CODE delimiters instead (# key among the options of the Advanced editor);
-starting off from the basics, is your version of Stata fully updated?

[Marcos Almeida]

Just as a side note to Carlo's helpful advices in #2 and #4, you may wish to post command as well as data, as you did in #1, but sharing an example which other members can work with.

In #1, unfortunately, there are unavailable variables, hence we cannot try to reproduce your problem.

Anyway, I suspect the issue may be related to the - gen - and - egen - commands you typed after creating the random numbers.