OpenEuphoria

Re: correlation coefficient program

• Posted by Ricardo Forno <ricardoforno at ?utopia.com> Sep 06, 2007
• 874 views

CChris wrote:
> 
> Jerry Story wrote:
> > 
> > Some time ago there was some discussion about correlation coefficient.
> > <a
> > href="http://www.openeuphoria.org/cgi-bin/esearch.exu?fromMonth=6&fromYear=2&toMonth=9&toYear=C&postedBy=Craig&keywords=%22correlation+coefficient%22">http://www.openeuphoria.org/cgi-bin/esearch.exu?fromMonth=6&fromYear=2&toMonth=9&toYear=C&postedBy=Craig&keywords=%22correlation+coefficient%22</a>
> > 
> > I swiped a huge bunch of data files and made a wxEuphoria-based program
> > using
> > Rob Craig's code.
> > <a
> > href="http://www3.telus.net/~jtstory/programs-unfinished/correlations.zip">http://www3.telus.net/~jtstory/programs-unfinished/correlations.zip</a>
> > 
> > Is there any use for this type of program?
> > 
> > The data files I used
> > <a
> > href="http://lib.stat.cmu.edu/DASL/allsubjects.html">http://lib.stat.cmu.edu/DASL/allsubjects.html</a>
> > don't seem to produce very useful results.
> > Is there any computer-readable data to make actually useful
> > correlations out of?
> 
> Most data series related with economics have high autocorrelation coefficients
> for small lags, because economic systems have a large inertia: the value you
> measure at some point will be quite strongly related to the one(s) you
> measured
> shortly before. Then you'll have useful stuff.
> 
> CChris


Correlation and autocorrelation are related concepts, but not the same.
Correlation refers to the relation between two parallel data series, for example
age and IQ, or country gross product and AIDS incidence, etc.
On the other hand, autocorrelation refers to the relation between a data series
and the same, displaced some places, which usually applies to data that is a
function of time.
A program to compute correlation may be usually applied also to compute
autocorrelation.
I haven't browsed the data you are referring to, but maybe you can try to
correlate different weather data: for example air humidity with rain next day,
etc.
Regards.