On 27 Oct 2000 15:02:50 GMT, [EMAIL PROTECTED] (Dubinse) wrote:
> I have the need to combine a number of data sets that are in the
> form of histograms where the class marks and boundaries may vary
> from data set to data set. The data represents numerical counts
> as a function of particle size on an asummedly continuoous scale.
> I want to combine some of the data to form a matrix with the rows
> representing the individual data sets and the columns representing
> the particle size on a single compatible scale. Eventually I want to
> calculate the variance/covariance matrix etc. In some cases the
> particle size scale is linear and in some cases it is logorithmic. I
> have not seen such matters treated in the literature, but I am mostly
> a country "hoss doctor" and not a professional statistician.
>
It seems to me that you might start with a set of box-and-whisker
plots. See Exploratory Data Analysis.
> Questions:
> (1) Are there methods described and software available for doing
> such aggregation of data?
I did not see you mention something that I would consider
"aggregation." Correlation is something other.
> (2) Are there pitfalls or violations of (sacred) assumptions involved
> im making such aggregations that would render the
> variance/covariance matrix invalid or otherwise debase further
> statistical operations that might ensue?
How do you want to weight by Ns? Keep in mind that you are *not*
interested in testing, and that you want to keep your descriptions as
clean and neat as possible. And check, earliest, with a local
statistician.
> (3) Is there some keyword, text, link etc I should examine in order
> to dispell my ignorance.
--
Rich Ulrich, [EMAIL PROTECTED]
http://www.pitt.edu/~wpilib/index.html
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