Dave,
The "outlier" package of R has a grubbs test
available:http://www.r-project.org/
Might need to be tweaked to run on Splus?
mike
>>> Dave Evens <devens8765@yahoo.com> Thursday, April 14, 2005 9:45:31
AM >>>
Dear All,
I have small samples of data (between 6 and 15) for
numerious time series points. I am assuming the data
for each time point is normally distributed. The
problem is that the data arrvies sporadically and I
would like to detect the number of outliers after I
have six data points for any time period. Essentially,
I would like to detect the number of outliers when I
have 6 data points then test whether there are any
ouliers. If so, remove the outliers, and wait until I
have at least 6 data points or when the sample size
increases and test again whether there are any
outliers. This process is repeated until there are no
more data points to add to the sample.
Is it valid to use the Grubbs test in this way?
If not, are there any tests out there that might be
appropriate for this situation? And, is this test
available in S-Plus? (Rosner's test requires that I
have at least 25 data points which I don't have.)
Thank you in advance for any help.
Dave
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