[R] Scatterplot Showing All Points

[Duncan Murdoch]

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