Re: st: Boxplots - avoiding the box in a strata with a small number of observations

[Nick Cox <njcoxstata@gmail.com>]

The difference between the two methods can be bridged by a -reshape-.

Nick

On Tue, Sep 4, 2012 at 12:56 PM, Richard Hiscock
<richardjhiscock@gmail.com> wrote:
> Thanks Nick for your help.
> The last method will provide me with the detail I need
> thanks Richard
>
>
> On 4 Sep 2012, at 18:54, Nick Cox wrote:
>
>> You can combine two or response variables with -by()- within -stripplot-.
>>
>> stripplot Baseline Firstdose Thirddose , by(wtstrata, row(1)) box vertical
>>
>> would be a start
>>
>> On Tue, Sep 4, 2012 at 9:07 AM, Nick Cox <njcoxstata@gmail.com> wrote:
>>> Allowing two or more -over()- options is characteristic only of -graph
>>> box-, -graph dot-, -graph bar- etc. It is not possible in practice
>>> with (a) -graph twoway- or (b) any command based on -twoway- such as
>>> -dotplot- (although (b) at least is programmable).
>>>
>>> -stripplot- (SSC) offers most if not of the flexibility you need. To
>>> concoct a problem similar to yours, I typed
>>>
>>> sysuse auto
>>> gen himpg = mpg > 20
>>>
>>> Then after some experimentation, this plot
>>>
>>> stripplot weight , over(rep78) by(himpg) vertical box(barw(0.5)
>>> blcolor(gs8))  width(100) center stack height(0.4)
>>>
>>> seems adequate.
>>>
>>> -stripplot- helps because
>>>
>>> 1. Both -over()- and -by()- are supported, thus allowing two-way
>>> classifications.
>>>
>>> 2. If a group contains only one value, the box would be a bar of zero
>>> length, which Stata won't (can't) show visibly.
>>>
>>> 3. You can adjust the box colour to play down the boxes while keeping
>>> them visible. I think this is a good idea generally.
>>>
>>> 4. You can tinker with bin width, spacing of points and box width
>>>
>>> Nick
>>>
>>> N.B. One stratum, two or more strata.
>>>
>>> On Tue, Sep 4, 2012 at 1:37 AM, Richard Hiscock
>>> <richardjhiscock@gmail.com> wrote:
>>>
>>>> I have continuous data (plasma level of drug) in patients, who received a dose determined by body weight (in five strata), measured at three time points.
>>>> Whilst the lower strata have 40+ patients the highest two levels the number of patients is very small n = 5 & 2.
>>>> To graphically present the plasma levels I would prefer to show individual data points but using dotplots however the command doesn't seem to allow for over commands (with data now in the long form).
>>>>
>>>> dotplot plasma_level , over(time) over(wtstrata)
>>>>
>>>> I can achieve close to what I want using boxplots, however I feel that boxes for the strata  with 5 & 2 only observations is not appropriate. Is there anyway to have individual data points displayed for these strata? The command I'm using in Stata 12 is
>>>>
>>>> gr box  Baseline Firstdose Thirddose , over(wtstrata)
>>>>
>>>> Any help or other presentation suggestions would be much appreciated
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>
>
> *
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