It looks like "ks.test" might help, but it seems to me you need to
make parsimonious models of the change in distributions, so you estimate
a few parameters for the distributions of each of your 4 data sets with
standard errors for all the parameters you estimate. Then you can test
if the change in the estimated parameters in going from A1 -> A2 exceeds
the change going from C1 -> C2 using z scores or t tests of the
differences in the parameter estimates -- or chi-squares / F's, etc., if
you want to do multiple dimensions all at once.
hope this helps. spencer graves
Peter Sebastian Masny wrote:
On Tuesday 08 June 2004 10:43 am, you wrote:
If I understand you correctly, you have two set of ***paired***
data, one set from the A population, and one from the C population.
Form the pairwise differences:
A.diff <- A1 - A2
C.diff <- C1 - C2
Alas, they are not paired. A1 and A2 are samples from the same population,
but of different members. Also, the number of measurements is different for
each dataset.
Boxplots and histograms of A.diff and C.diff will tell you
(much more than a test ever would) what's ***really*** going on.
The boxplots I have clearly show the difference, but I need a p value to go
with it.
Here are the boxplots if that helps:
http://www.ps.masny.dk/guests/misc/A1.png
http://www.ps.masny.dk/guests/misc/A2.png
http://www.ps.masny.dk/guests/misc/C1.png
http://www.ps.masny.dk/guests/misc/C2.png
P.S. BTW --- you say that your data are continuous, but that their
distributions are ``more like a Poisson''. The Poisson distribution
is DISCRETE!!!
Hence the "like". The data is indeed continuous, but a distribution graph
increases towards one extreme...
Visually, the results are convincing, but I really need a test of
significance.
Thank you very much for the help,
Peter
______________________________________________
[EMAIL PROTECTED] mailing list
https://www.stat.math.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
______________________________________________
[EMAIL PROTECTED] mailing list
https://www.stat.math.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
