# Re: st: referencing eresult matrices

 From Austin Nichols To statalist@hsphsun2.harvard.edu Subject Re: st: referencing eresult matrices Date Sat, 7 Nov 2009 12:16:49 -0500

```One way:
mata:st_matrix("e(b)")[1,1]

On Fri, Nov 6, 2009 at 8:36 AM, Nick Cox <n.j.cox@durham.ac.uk> wrote:
> I don't know one. I guess the low-level syntax parser needs a subscript to be preceded by a matrix or variable name and tweaking it so this could be understood is more bother than it's worth. As you know, you have to worry about what such a change might break.
>
> Nick
> n.j.cox@durham.ac.uk
>
> Jeph Herrin
>
> Thanks, but as the subject line says, I want to
> reference e(matrix) directly - I just gave one
> example. I've been using the below method for years,
> so I hardly think about it anymore, but every once
> in a while wonder if there's a shorter way.
>
> Maarten buis wrote:
>
>> --- On Thu, 5/11/09, Jeph Herrin wrote:
>>> After an estimation, I often want to get a particular
>>> element of one of the result matrices, and know I can do
>>> it as follows:
>>>
>>>   reg y x
>>>   matrix b = e(b)
>>>   di el("b",1,1)
>>>
>>> But there must be a way to eliminate the middleman b? This
>>>
>>>   reg y x
>>>   di el("e(b)",1,1)
>>>
>>> doesn't work, but I'm sure there's a way to reference e(b)
>>> so that I don't need to store it in another matrix first.
>>> In fact, I'm sure I knew it once, even.
>>
>> Say the variable whose coefficient you want is called x,
>> than you can refer to it as _b[x] (and its standard error as
>> _se[x]).
>>

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```