# st: RE: Number of observations in a matrix -codebook- -makematrix-

 From "Nick Cox" <[email protected]> To <[email protected]> Subject st: RE: Number of observations in a matrix -codebook- -makematrix- Date Wed, 9 Apr 2008 19:04:42 +0100

```Here is one way to get that number into a matrix:

count if country=="GBR" & post_ifrs==1 & ib_scaled!=. & ib_scaled2!=. &
sample_sum==1
mat A = J(1,1,.)
mat A[1,1] = r(N)

If -count- catches duplicates, do this downstream of a use of -egen,
tag()-.

If you use -makematrix- you need to use the -vector- option.
But doing it directly looks easier to me.

Nick
[email protected]

Herve STOLOWY

I have a sample with 403 companies and 822 observations (several years
per company). I would like to report the 403 figure in a matrix (to
export it later in  a table).

With the following command,
codebook name if country=="GBR" & post_ifrs==1 & ib_scaled!=. &
ib_scaled2!=. & sample_sum==1
I get the correct figure for unique values (403). However, I don't find
this figure in the return list.

With -tabulate- and the following command:
tabulate name if country=="GBR" & post_ifrs==1 & ib_scaled!=. &
ib_scaled2!=. & sample_sum==1

I get the correct figure in the return list: r(r)

ssc):

makematrix c1, from(r(r)) label listwise: tabulate name if
country=="GBR" & post_ifrs==0 & ib_scaled!=. & ib_scaled2!=. &
sample_sum==1

I get an error message: too many values.

Would you have an idea about how to get the 403 figure in a matrix?

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