Mata Stata behave Strangly

[Saeed Sardar]

I am starting this new thread because the problem I was facing before has now changed. I am trying to define a mata function, that uses Stata's IF argument. I have managed to do it with some success, however, after the function is executed, and I return to Stata, it will show dot and not execute any command unless I press the close curly brackedt i.e. }. I do not understand why this happens

mata
mata clear
void f()
{
stata(`"if year(date("$S_DATE", "DMY"))<2016{"')
stata(`"display as error "Ticket has expired, please renew it ""')
stata("}")

}

mata mosave f()
end
mata: f()

[Niels Henrik Bruun]

I agree with Nick - I do not understand what it is for.
Further I do understand why you insist of running everything within stata when you in fact are working in Mata.

But I think this will help:

. mata
------------------------------------------------- mata (type end to exit) ----------------
:         mata clear

:         void f(real scalar year)
>         {
>                 if ( year(date("$S_DATE", "DMY")) > year ) {
>                         printf(`"{error:Ticket has expired, please renew it}"')
>                 } else {
>                         printf(`"Everything is fine"')
>                 }
>         }

: end
------------------------------------------------------------------------------------------

. mata: f(2016)
Ticket has expired, please renew it
. mata: f(2018)
Everything is fine

[Saeed Sardar]

Thank you Niels Henrik Bruun, you solution worked. I am not comfortable in mata, but need this mata function as it can be locked from reading, while Stata programs are open for all to see. I am not still getting what was wrong with my earlier post.

[Joseph Coveney]

Stata's command line language is interpreted, I believe, and so it waits for the closing brace. I'm not sure that Stata's interpreter will even return control to Mata until then. I recommend avoiding trying to execute mulitline Stata commands like that from Mata.

As Nick and Niels have both suggested, it's better to work within Mata.