Differentiating between extended missings in -misstable- or -missings report-

[Jorgen Carling]

Dear Statalist,

I am struggling to create a single table of missing values for all variables, that differentiates between each type of extended missing (.a, .b, etc). neither -misstable summarize- nor -missings report- seem to have this functionlaity (though both can differentiate system missings (.) from _all_ extended misssings (total of .a, .b, etc). The user-written -misschk- seems to have the required option, but -misschk- is no longer possible to install, it seems.

Here is the result I want (with or without additional columns, preferable listing all variables regardless of the presence of missings)

          .a     .b
------------------------------------
var1       0     32
var2      12     64
...

Many thanks for your advice!

[Nick Cox]

I don't know anything about misschk. I know more about missings, as I wrote it.

missings is also user-written (community-contributed is now the recommended jargon). In an up-to-date Stata, search missings, sj will find details; otherwise you may need the more unpredictable

. search dm0085, entry

Search of official help files, FAQs, Examples, and Stata Journals

SJ-20-4 dm0085_2  . . . . . . . . . . . . . . . . Software update for missings
        (help missings if installed)  . . . . . . . . . . . . . . .  N. J. Cox
        Q4/20   SJ 20(4):1028--1030
        sorting has been extended for missings report

SJ-17-3 dm0085_1  . . . . . . . . . . . . . . . . Software update for missings
        (help missings if installed)  . . . . . . . . . . . . . . .  N. J. Cox
        Q3/17   SJ 17(3):779
        identify() and sort options have been added

SJ-15-4 dm0085  Speaking Stata: A set of utilities for managing missing values
        (help missings if installed)  . . . . . . . . . . . . . . .  N. J. Cox
        Q4/15   SJ 15(4):1174--1185
        provides command, missings, as a replacement for, and extension
        of, previous commands nmissing and dropmiss

This problem exposes something that missings cannot do, but makes perfect sense, so I will look into extending the code. Meanwhile here are some experiments with countvalues from SSC, discussed at https://www.statalist.org/forums/for...lable-from-ssc

clear 
input testvar1 
1      
2
3
.
.a
.b
.z 
end

gen testvar2 = testvar1 

gen testvar3 = cond(_n == _N, 1.23, .z)

list

Here is the test dataset.

. list 

     +--------------------------------+
     | testvar1   testvar2   testvar3 |
     |--------------------------------|
  1. |        1          1         .z |
  2. |        2          2         .z |
  3. |        3          3         .z |
  4. |        .          .         .z |
  5. |       .a         .a         .z |
     |--------------------------------|
  6. |       .b         .b         .z |
  7. |       .z         .z       1.23 |
     +--------------------------------+

What is easy is when you know what you are looking for:

countvalues testvar*, values(.a .b .z)

  +-------------------------+
  |     name   .a   .b   .z |
  |-------------------------|
  | testvar1    1    1    1 |
  | testvar2    1    1    1 |
  | testvar3    0    0    6 |
  +-------------------------+

But a fair task is for Stata to work out which missing values exist anywhere in a bunch of variables. Here is my best stab at that so far.

foreach v of var testvar* {
    levelsof `v' if missing(`v'), missing clean local(this)
    local levels `levels' `this'
}

local levels : list uniq levels 
local levels : list sort levels 

countvalues testvar*, values(`levels')

.
.
with results

 
  +-----------------------------+
  |     name   .   .a   .b   .z |
  |-----------------------------|
  | testvar1   1    1    1    1 |
  | testvar2   1    1    1    1 |
  | testvar3   0    0    0    6 |
  +-----------------------------+

[Jorgen Carling]

Thank you!

I was not aware of countvalues, and

countvalues, values(. .a .b)

gives me exactly what I need. And it would be great if an updated version of -missings- incorporates this possibility!

[Nick Cox]

https://www.statalist.org/forums/for...updated-on-ssc advertises an update to missings on SSC. Thanks for the stimulating question!