Re: st: graphing ratio as a function of a continuous variable

[Nick Cox <njcoxstata@gmail.com>]

My interpretation is the same as Maarten's. The ratio 0/1 is not
interesting and the ratio 1/0 is not useful, so it seems more likely
that you are concerned with how the proportion of something varies.

I'll add that Maarten's -proprcspline- (SSC) is a really splendid
program for this purpose. If you want something more discrete, there
is a worked example in the help for -stripplot- (SSC) which shows how
a smooth summary can be superimposed on a strip plot of the indicator
variable.

Nick

Maarten buis

> From your describtion it looks like you have a proportion (which
> is ofcourse a special case of a ratio) but from your example it
> looks like you have a variable that only takes values 0 or 1
> which is typically not called a ratio but rather a indicator or
> dummy variable.
>
> If the former is true I would just show a scatter plot with
> your proportion on the y-axis and your continuous variable on
> the x-axis.
>
> If the latter is true I would add a smooth average to the plot,
> e.g. using Nick Cox's -rcspline- or my -proprcspline-. Both can
> be downloaded from SSC by typing -ssc install rcspline- and
> -ssc install proprcspline- respectively. Both commands allow the
> -addplot()- option for extra overlaid graphs.

Delahanty, Ryan

>> In Stata 11 I'm trying to graph how
>> the ratio of something (a 1 or a 0--say foreign and domestic
>> in the auto dataset) varies as a function of a continuous
>> variable (say price). Is there a good way to do this and
>> simultaneously generate overlaid graphs?
*
*   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/