Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: st: Loops in Mata
From
Nick Cox <[email protected]>
To
[email protected]
Subject
Re: st: Loops in Mata
Date
Wed, 26 Jan 2011 10:24:54 +0000
It seems that you may be expecting Mata's -for- to behave a bit like
Stata's -foreach- and perform a kind of macro substitution. -for- does
not work like this.
On Wed, Jan 26, 2011 at 10:18 AM, Nick Cox <[email protected]> wrote:
> As far as Mata is concerned, it looks as if you are asking it to do
> the same calculation 379 times on a variable called -Pi-.
>
> You want Mata to cycle over 379 different variables, which is a very
> different problem. It's probably better to read in all the data at
> once to a matrix, then loop over the column vectors.
>
> Nick
>
> On Wed, Jan 26, 2011 at 10:08 AM, gsborker <[email protected]> wrote:
>
>> I am trying to do the following in mata
>>
>> mata
>>
>> for (i=1; i<=379; i++) {
>>
>> xi = st_data(.,"Pi") ;
>> yi = (xi)' ;
>> polyroots(yi) ;
>>
>> }
>> end
>>
>> where P* are (674x1) column vectors. I am trying to run the "polyroots"
>> command 379 times on (1x674) row vectors. This is not working and I'm
>> getting recurrent errors.
>
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/