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# Re: st: Append new row to existing matrix

 From "Sandy Y. Zhu" To statalist@hsphsun2.harvard.edu Subject Re: st: Append new row to existing matrix Date Sat, 24 Mar 2012 19:28:20 -0400

```Thank you!

Would some one mind telling me what this portion of the code means?

>        qui gen x`i'=uniform()
>        qui reg y x`i'

I'm trying to run a multivariate regression, so should I do multiple
qui gen x`i'?

Thanks!

2012/3/24 Jorge Eduardo Pérez Pérez <perez.jorge@ur.edu.co>:
> clear
> set obs 100
> gen y=uniform()
> forv i=1(1)100 {
>        qui gen x`i'=uniform()
>        qui reg y x`i'
>        matrix b=e(b)
>        if `i'==1 matrix betas=b
>        else matrix betas=(betas \ b)
>        drop x`i'
> }
> matrix list betas
>
> Also, take a look at -statsby-
> _______________________
> Jorge Eduardo Pérez Pérez
>
>
>
> On Sat, Mar 24, 2012 at 7:11 PM, Sandy Y.  Zhu <sandy.zhu@yale.edu> wrote:
>> Hi guys:
>>
>> How can I append a new row to an existing matrix? Basically, I'm
>> trying to update the matrix in a loop,
>>
>> I have:
>>
>> for i=1 to 900
>> {reg y x1 x2 x3
>> mat beta=e(b)
>>
>> append e(b) to an existing matrix}
>>
>> Basically, I  have 900 regressions to run, and I  need to save the
>> beta values from each regression. I would like to save them all in a
>> matrix, so the first row in the matrix saves the betas from the 1st
>> regression, the 2nd row would save the coefficients from the 2nd
>> regression, etc....
>>
>>
>> Thank you!
>>
>> --
>> Yours sincerely,
>>
>> Sandy Y. Zhu
>> *
>> *   For searches and help try:
>> *   http://www.stata.com/help.cgi?search
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>> *   http://www.ats.ucla.edu/stat/stata/
>>
>>
>
>
> *
> *   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/

--
Yours sincerely,

Sandy Y. Zhu

*
*   For searches and help try:
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*   http://www.stata.com/support/statalist/faq
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```