fisher.sum: A function to calculate Fisher's sum for a set of p-values
Description
This method combines a set of p-values using Fisher's method:
$$S = -2 \sum \log p$$
Usage
fisher.sum(p, zero.sub=0.00001, na.rm=FALSE)
Arguments
p
A vector of p-values
zero.sub
Replacement for 0 values.
na.rm
Should NA values be removed before calculating the sum
Value
Fisher's sum as described above.
Details
As log(0) results in Inf we replace p-values of 0 by
default with a small float. If you want to keep them as 0 you have
to provide 0 as a parameter in zero.sub.
Note that only p-values between 0 and 1 are allowed to be passed to
this method.
References
Fisher, R.A. (1925). Statistical Methods for Research Workers. Oliver
and Boyd (Edinburgh).