[R] scatterplot and correlation for weird data format

Jim Lemon jim at bitwrit.com.au
Tue Feb 17 12:02:24 CET 2009


William Simpson wrote:
> I have data in a format like this:
>
> name	ssex	sex	view	num	rating	rt
> ahl4	f	m	f	56	-108	2246
> ahl4	f	m	f	74	85	1444
> ahl4	f	m	f	52	151	1595
> ahl4	f	m	f	85	1	1447
> ahl4	f	m	f	53	46	1716
> ahl4	f	m	f	37	145	1276
> ahl4	f	m	f	50	98	1465
> ahl4	f	m	f	51	-26	1322
> ahl4	f	m	f	38	-97	1790
> ahl4	f	m	f	14	-158	865
> ...
> ahl4	f	m	p	43	-136	1669
> ahl4	f	m	p	10	-59	808
> ahl4	f	m	p	67	-111	1279
> ahl4	f	m	p	85	-86	994
> ahl4	f	m	p	100	134	1337
> ahl4	f	m	p	76	56	665
> ahl4	f	m	p	51	-49	594
> ahl4	f	m	p	33	-118	505
> ahl4	f	m	p	49	-156	1283
> ...
> and so on for many subjects (name)
>
> I would like to do a scatterplot of the rating given by each subject
> (with identifier "name") for the frontal (view=="f") and profile
> (view=="p") views of each face (each face has an identifier "num").
> I'd like to find the correlation as well.
> For each subject, since there are 100 faces, there will be 100 points
> on the scatterplot. I would just lump all the subjects' data together
> for the plot and correlation I think (unless somebody tells me I
> should do each subject separately).
>
> I'm stumped on how to do this. Thanks very much for any help!
>   
Hi Bill,
The first thing that comes to mind is a variation on count.overplot, a 
function that displays the number of overplotted points for a given 
tolerance rather than a blur of separate symbols. The problem would be 
separating the various categories of experimental stimuli in your case. 
You could use, say, "F" and "P" as suffixes for the counts to indicate 
orientation, color to indicate sex of face, male/female symbol for sex 
of respondent, and so on. The problem is that you end up with a 
difficult to interpret plot, as each entry (of which there will still be 
many) must be decoded by the viewer. If you think this is worth 
pursuing, email me and I will try to outline a way to do it.

Another, perhaps simpler way is to define a summary score for each 
subject for each class of face and plot that.

Jim




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