Problem with "paralell" module when bootstrapping

[jomike]

Dear Statalist community!
To increase speed of a bootstrapping program, I tried out the "paralell" modul (https://github.com/gvegayon/parallel). Unfortunately, I get weird error message when trying to run parallel in my setting. Its most probably a very simple problem, but I cannot figure out. Any help is highly appreciated.

My Stata version: 15.1

I installed "paralell" modul as indicated on Github:

ssc install parallel, replace
parallel setclusters 4, f

***************************************
My do-file:

est clear
global variab "laborforce "

This here is my "program":

capture program drop bivprobit_boot
program bivprobit_boot, rclass
set more off
*the following four lines refer to macros that I use to run the biprobit model
foreach var in $variab{
foreach bw in obw {
foreach per in per_base`var'`bw' {
foreach ff in per_ff`var'`bw'{
*baseline model
biprobit (`var' = takeup $`ff' i.year ) (takeup = i.treat $`ff' i.year ) if $`per', cluster (hhid)
eststo base`var'_`bw'
*predict
predict x1b1hat , xb1
gen x1b1hat0 = x1b1hat- _b[takeup]*takeup
gen x1b1hat1 = x1b1hat0 + _b[takeup]
gen pe1 = normal(x1b1hat1) - normal(x1b1hat0)
summarize pe1
return scalar ape1= r(mean)
drop x1b1hat x1b1hat0 x1b1hat1 pe1
}
}
}
}
end

Here starts the actual bootstrapping. When trying to run this I get the error message....

foreach var in $variab {
*bootstrapping
parallel bs r(ape1), reps(50) seed(123): bivprobit_boot
eststo bootstr`var'obw
}

***********************************
Stata output:

. foreach var in $variab {
2. *bootstrapping
. parallel bs r(ape1), reps(50) seed(123): bivprobit_boot
3. eststo bootstr`var'obw
4. }
invalid 'reps'
r(198);

***********************************

Does anyone have an idea what the problem could be?
I'd appreciate this a lot!

Best,

Johanna

[Mike Lacy]

From reading the help file for -parallel- (ssc describe parallel), I see a couple of problems:

parallel bs [, expression(exp_list) programs(namelist) mata noglobal seeds(numlist) randtype(current|datetime|random.org) timeout(integer) processors(integer) bs_options ] [: command]

1) You need "expression(r(ape1))", and it must occur after the the comma. This is likely creating the r(198) error.
However:
2) The seeds() option requires more than one seed.

-parallel- is a very impressive program, but in playing around with it a few times, I have found it difficult to properly follow the syntax. Also, at least for me, there is a bug in its updated help file, which makes it hard to read. I would suggest you try to get a simple example of -parallel- to run, and then work your way up to your fancier application. I for one would be interested to see a report back from you on what happens. I suspect we may need to get its creator/maintainer involved before we're done.