grubbs.test
Dear Dave, I do not know the grubbs.test (is it a function, where can I find it?) and probably n=6 data points are really few.. Having said that, what do you mean as "outlier"? If you mean deviation from the estimated mean (of previous data), you might have a look to the strucchange package..(sorry, but now I do not remember the exact name of the function) best, vito
Dave Evens wrote:
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? Rosner's test required 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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