Message-ID: <476741F6.7040005@stats.uwo.ca>
Date: 2007-12-18T03:43:50Z
From: Duncan Murdoch
Subject: Scatterplot Showing All Points
In-Reply-To: <1197940463.47671eef4045e@webmail.fas.harvard.edu>
On 17/12/2007 8:14 PM, Wayne Aldo Gavioli wrote:
>
> Hello all,
>
>
> I'm trying to graph a scatterplot of a large (5,000 x,y coordinates) of data
> with the caveat that many of the data points overlap with each other (share the
> same x AND y coordinates). In using the usual "plot" command,
>
>
>> plot(education, xlab="etc", ylab="etc")
>
>
> it seems that the overlap of points is not shown in the graph. Namely, there
> are 5,000 points that should be plotted, as I mentioned above, but because so
> many of the points overlap with each other exactly, only about 50-60 points are
> actually plotted on the graph. Thus, there's no indication that Point A shares
> its coordinates with 200 other pieces of data and thus is very common while
> Point B doesn't share its coordinates with any other pieces of data and thus
> isn't common at all. Is there anyway to indicate the frequency of such points
> on such a graph? Should I be using a different command than "plot"?
The jitter() function can add a bit of noise to your data, so that
repeated points show up as groupings instead of isolated points.
Duncan Murdoch