# st: RE: how to prevent omission of zeroes in frequency tab

 From "Nick Cox" <[email protected]> To <[email protected]> Subject st: RE: how to prevent omission of zeroes in frequency tab Date Thu, 28 Jul 2005 18:28:01 +0100

```The user-written program -tabcount- from SSC addresses
this problem. There was a discussion in

Speaking Stata: Problems with tables, Part II.
SJ 3(4): 420--439 (2003).

Nick
[email protected]

A.M. Vos

> I have patient data, with one record for each patient, and about 100
> variables.
> I try to make many similar frequency tables of the variables ORIGIN,
> TOTDELKL, which should look like:
>                 TOTDELKL1  TOTDELKL2 TOTDELKL3 etc
> africa
> america
> europe
> etc
>
> such tables have to be made for each possible combination of
> the values
> of the variables (with possible values as specified) YOUNG (1,2),
> TSI(1-5), REDENOZ(1,2), CLUSPL(0,1,2). Thus I should obtain 2*5*2*3=60
> tables.
>
> However, some of these tables will contain only zeroes, since
> no patient
> has their combination of values. There may also be tables
> where a whole
> row or a whole column contains zeroes, since no patient has the value
> africa in the variable ORIGIN or no patient has the value 2 in the
> variable TOTDELKL, etc.
>
> here is a piece of my syntax:
>
> > use "mydata.dta", clear
> > keep if (YOUNG==1 & TSI==1 & REDENOZ==1 & CLUSPL==0)
> > preserve
> > contract ORIGIN TOTDELKL, zero
> > reshape wide _freq, i(ORIGIN) j(TOTDELKL)
>
> the problem is, that if the combination YOUNG==1 & TSI==1 &
> REDENOZ==1 &
> CLUSPL==0 does not exist at all, this syntax results in a
> "dataset" with
> all 100 original variables, but no observations (I prefer to get the
> specified frequency table with only zeroes),
>
> and more important, if the combination does exist, but there are no
> observations for ORIGIN=africa, or no observations for
> TOTDELKL=1, than
> I get a table where africa is omitted or TOTDELKL 1 is omitted. This
> makes my 60 tables difficult to compare.
> Is there a way to obtain empty tables / columns / rows in the
> specified format?

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