Hello William,
thank you for the explanation and the example.
Regards, Sergiy
On 8/27/07, William Gould, StataCorp LP <[email protected]> wrote:
> Sergiy Radyakin <[email protected]> reports,
>
> > I want to return a string among the r() values from a Mata function.
> >
> > According to the manual, the following function is to be used in this case:
> > > st_strscalar(string scalar name, string value)
> > [...]
> >
> > It does not seem to work however. The following is what happened:
> > **-------------1--------------------------------------------------
> > : mata clear
> > : void function my_test() {
> > > st_strscalar("r(my_name)" ,"my_value")
> > > }
> > : my_test()
> > st_strscalar(): 3300 argument out of range
> > my_test(): - function returned error
> > <istmt>: - function returned error
> > r(3300);
> >
> > As an alternative, I tried to store my string value to a local via st_local:
> > **-------------2--------------------------------------------------
> > : mata clear
> > : void function my_test() {
> > > st_local("r(my_name)" ,"my_value")
> > > }
> > : my_test()
> > _r(my_name) invalid name
> > st_local(): 3300 argument out of range
> > my_test(): - function returned error
> > <istmt>: - function returned error
> > r(3300);
>
> First, "string scalars" are not currently allowed in r(), and that is why
> Mata gave an error when Sergiy coded
>
> st_strscalar("r(my_name)" ,"my_value")
>
> What he coded would be correct syntax if Stata had string scalars.
>
> Stata expects strings in r() to be returned in macros. Sergiy tried,
>
>
> st_local("r(my_name)" ,"my_value")
>
> but that did not work. What would have worked is
>
> st_global("r(my_name)" ,"my_value")
>
> and here's a demonstration:
>
> . mata
> ----------------------------------------- mata (type end to exit) -----
> : st_rclear()
>
> : st_global("r(myname)", "a string value")
>
> : end
> -----------------------------------------------------------------------
>
> . ret list
>
> macros:
> r(myname) : "a string value"
>
> . _
>
> It's a fine point, but things like r(myname) are considered to be global
> macros and not local macros because those macros are exposed outside of
> the program that set them.
>
> -- Bill
> [email protected]
> *
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>
*
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