Displaying 2 results from an estimated 2 matches for "_biometry_".
2000 Sep 21
2
qqnorm(), is it "backwards"?
...ance: if I qqnorm() bimodal or uniform data I get a sigmoidal in
which the qqnorm() points lie above the qqline() at -ve theoretical
quantiles, and the qqnorm() points lie below the qqline() at +ve
theoretical quantiles. Yet I expect such platykurtic distributions to go
the other way (eg pg 117 in _Biometry_ Sokal & Rohlf, 3rd ed).
The same thing with skewed data, I expect right skewed data to show a
negatively accelerating shape, but qqnorm() curves upwards.
Am I missing something, or is qqnorm() consistently heading in the wrong
diirection?
Cheers,
-P.
--
Peter L. Hurd, Ph.D.
phurd at uts.c...
2002 Apr 15
1
nested anova not giving expected results
...atistics in nested
anovas in R. If I understand correctly, the F statistic for the
among-subgroups but within groups hypothesis is calculated as
MS_subgroups/MS_error, while the F statistic for the factor is calculated as
MS_factor/MS_subgroups (I'm getting this from Sokal & Rohlf's _Biometry_).
However, as I understand the output from R, it calculates the F for the
factor as MS_factor/MS_error, which can significantly change the results.
As an example, I took the values from Sokal & Rohlf's example on mosquitos,
which are as follows:
cage animal length
1 1 a 5...