# st: RE: RE: AW: RE: display all categories on pie chart for categorical variables (with some zero values)

 From Adam Collins To "statalist@hsphsun2.harvard.edu" Subject st: RE: RE: AW: RE: display all categories on pie chart for categorical variables (with some zero values) Date Fri, 27 Nov 2009 14:42:47 +0100

```Apologies for the delay replying, something urgent came up yesterday.

Thank you so much Martin and Nick!!!  This is a fantastic solution!  I don't quite understand the theory behind it, but it works like a treat.

I notice that now, to display just one of my categorical variables on it's own (but with all the categories listed in the legend), it is as simple as:

graph pie plotvar if _j==1, over(c) allcategories

or

graph pie plotvar if _j==2, over(c) allcategories

Even more excitingly, I see that the same thing can now be applied to bar graphs, and that it solves the problem of displaying all the categories in the "correct" order on the bar graph - even if some of them containing zero occurrences:

gen one=1
graph hbar (sum) one if _j==2, over(c) allcategories

Many thanks!

-----Original Message-----
From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Nick Cox
Sent: jeudi 26 novembre 2009 15:02
To: statalist@hsphsun2.harvard.edu
Subject: st: RE: AW: RE: display all categories on pie chart for categorical variables (with some zero values)

This is the code to get Martin's graphs from Martin's data, but using

clear

inp byte(a b)
2 3
4 5
7 2
3 6
9	10
end

gen plotvar=abs(rnormal())

gen id = _n

rename a c1
rename b c2

reshape long c, i(id)
label define _j 1 "a" 2 "b"
label val _j _j

graph pie plotvar, over(c) by(_j)

Nick
n.j.cox@durham.ac.uk

Martin Weiss

This at least gives you all the categories:

*************
clear*

inp byte(a b)
2 3
4 5
7 2
3 6
9	10
end

gen plotvar=abs(rnormal())

compress
list, noo

preserve
tempfile mytemp
//get unique values of a and b jointly
stack a b, into(c) clear
duplicates drop c, force
drop _stack
save `mytemp', replace
restore

//for a
preserve
keep a plotvar
rename a c
l
merge 1:1 c using "`mytemp'"
replace plotvar=0 if mi(plotvar)
graph pie plotvar, over(c) missing  /*
*/ name(mygra, replace) tit(for a) /*
*/ nodraw
restore

//for b
preserve
keep b plotvar
rename b c
l
merge 1:1 c using "`mytemp'"
replace plotvar=0 if mi(plotvar)
graph pie plotvar, over(c) missing  /*
*/ name(mygrb, replace) tit(for b) /*
*/ nodraw
restore

graph combine mygra mygrb
*************

I expect there is something really simple that I am missing here... but
I am
new to Stata and it is doing my head in that I can't display all
categories
of a categorical variable on a pie chart...  I am really getting no
where
with this problem.  I would really appreciate some help.

I tried exploring ways of storing the "counts" from my categorical
variable
values in another variable, such as a matrix which would allow me to
store a
"zero count" as a "0" value.  In searching for a solution, I came
accross
-fulltab- (from SSC), however it doesn't seem to work (it just displays
the
following "program error:  code follows on the same line as open
brace").

Anyway, I am not even sure this is the best approach.  Surely there is
something more straight forward?

-----Original Message-----
From: owner-statalist@hsphsun2.harvard.edu
[mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Adam Collins
Sent: mercredi 25 novembre 2009 17:39
To: statalist@hsphsun2.harvard.edu
Subject: st: display all categories on pie chart for categorical
variables
(with some zero values)

Hello,

I have several categorical variables that each possess the same list of
categories (value labels).

To enable easy comparison of the pie charts, I would like every category
to
exist on every chart (so that each category retains the same
colour/settings/legend position etc on each chart).

The problem is that some of the variables contain zero occurrences of
certain values (categories) and the standard 'over(varname)' option with
-graph pie- excludes categories with no occurrences.  I have tried the
'allcategories' option, but since it applies to the 'over()' variable,
it
does not help.

Does anyone have any ideas?  (by the way, since this is for a specific
set
of categorical variables, it is fine if the categories are 'hard coded',
then applied to each variable)

*
*   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/

*
*   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/
```