search for: 27s_method

Displaying 2 results from an estimated 2 matches for "27s_method".

2013 Mar 28
2
hierarchical clustering with pearson's coefficient
...lation as distance between observations and then use any centroid based linkage distance (ex. Ward's distance) When linkage distances are formed as the Lance-Williams recursive formulation, they just require the initial distance between observations. See here: http://en.wikipedia.org/wiki/Ward%27s_method It is said that you have to use euclidean distance between the initial observations. However i have found this: http://research.stowers-institute.org/efg/R/Visualization/cor-cluster/ where they use pearson's correlation for hierarchical clustering. Any idea if anything is violated in case p...
2012 Oct 31
0
combined dependent pvalue
...5): fisher.comb <- function (pvalues) { df=length(pvalues) ch2=(-2*sum(log(pvalues))) return pchisq(ch2, df=df, lower.tail=FALSE) } For combination of dependent p-value, I could not find any R code here but there is a method from Brown (http://en.wikipedia.org/wiki/Extensions_of_Fisher%27s_method#Brown.27s_method), in which it is still combine p value in the same way, the only difference is the Chi square distirbution's variance is different from the previous method (using the covariance of the p values). I am not sure how to migrate from the traditional fisher's method to brown...