Hi,
When performing a ttest, the qq plot sometimes only shows the diagonal line, with no points.
I think I found the problem is when there are missing values in both groups being compared.
The code in ttestISClass should remove NAs in line
pieces <- lapply(pieces, function(y) y - mean(y))
i.e.
pieces <- lapply(pieces, function(y) y - mean(y, na.rm=TRUE))
or remove NAs before for x & y
When NAs are in one group only, points are shown, but I suppose are only for the group without missings.
qqplot in ttest
Re: qqplot in ttest
hi,
could you attach a .omv file, or some example code which does this?
with thanks
could you attach a .omv file, or some example code which does this?
with thanks
Re: qqplot in ttest
Hi,
I noticed the problem analyzing the variable glyhb from the diabetes dataset from here:
http://biostat.mc.vanderbilt.edu/wiki/Main/DataSets
Victor
I noticed the problem analyzing the variable glyhb from the diabetes dataset from here:
http://biostat.mc.vanderbilt.edu/wiki/Main/DataSets
Victor
- Attachments
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- Sample output
- analysis.png (172.98 KiB) Viewed 3000 times
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- diabetes.omv
- Sample data
- (55.12 KiB) Downloaded 353 times
Re: qqplot in ttest
oh yup. fixed, will be in the next release.
and it looks like this
thanks for reporting
jonathon
and it looks like this
thanks for reporting
jonathon