Richard Sherman asked:
----------------------------------
Here is what must be a simple graphing problem; I confess that I am
still mostly baffled by the Stata 8 graphics syntax.
I have seven variables, c1-c7, that take values 1, 2, or 3. I want a
graph of the frequencies of these variables that looks something like
this:
freq |
|
|
| *
| * *
| * *
| * * *
| * * * * * *
| * * * * * * * * *
|________________________________________ (... etc.)
1 2 3 1 2 3 1 2 3 (... etc.)
c1 c2 c3 (... etc.)
I have been slogging away with -graph bar- and have gotten no farther
than the inelegant and unsatisfying method of generating three
variables from each variable (measuring the count of each category) and
using
graph bar (count) all-of-these-variables
or
graph bar (count) three-at-a-time
and then
graph combine these-seven-graphs
But surely there is a better way. Thanks in advance for any help.
-------------------------------------------------------------------
Clive Nicholas suggested
...
> use Nick Cox's -catplot- routine, downloadable via SSC.
...
> > to do something like:
> >
> > . catplot bar continuousvar, over(discretevar) sort percent asyvars
> >
> > But even this doesn't quite do what Richard wants, which is
> to bar-graph
> > seven _individual_ variables which all have (presumably)
> the same three
> > categories _without_ having to specify an -over()- option.
Scott Merryman then suggested
> Ok, how about something like this:
>
> *Create data set: 7 variables with values {1, 2, 3}
> clear
> set obs 30
> qui {
> forv i = 1/7 {
> gen c`i' = 1
> replace c`i' = 2 if uniform() <.4
> replace c`i' = 3 if uniform() <.3
> }
> }
>
> *Create frequency values
> qui {
> forv i = 1/7 {
> tempfile file`i'
> xcontract c`i', freq(freq) idnum(`i') saving(`file`i'')
> }
> }
>
> dsconcat `file1' `file2' `file3' `file4' `file5' `file6' `file7'
> drop c*
> egen id2 = fill(1 2 3 1 2 3)
>
> forv i = 1/7 {
> local relabel `relabel' `i' C`i'
> }
>
> graph bar freq, over(id2) over(idnum, relabel( `relabel'))
> ytitle(Frequency)
Taking the idea from Clive of using -catplot- and from
Scott that a data restructure is needed, another way is along
these lines. First we create an example dataset as did
Scott
clear
set obs 30
qui forv i = 1/7 {
gen c`i' = 1
replace c`i' = 2 if uniform() <.4
replace c`i' = 3 if uniform() <.3
}
Then
gen id = _n
reshape long c , i(id)
catplot bar c _j
There is no need to get into file manipulations,
as all can be done in place.
Nick
[email protected]
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