# sump: Combine p-values using the sum of p (Edgington's) method In metap: Meta-Analysis of Significance Values

 sump R Documentation

## Combine p-values using the sum of p (Edgington's) method

### Description

Combine \mjseqnp-values using the sum p method\loadmathjax

### Usage

sump(p)
## S3 method for class 'sump'
print(x, ...)


### Arguments

 p \sigvec x An object of class ‘sump’ ... Other arguments to be passed through

### Details

Defined as \mjdeqn\frac(\sum_i=1^k p_i)^kk! - k \choose 1\frac(\sum_i=1^k p_i - 1)^kk! + k \choose 2\frac(\sum_i=1^k p_i - 2)^kk! ... ((sum p) ^ k) / k! - (k-1)C(1) ((sum p - 1) ^ k) / k! + (k-2)C(2) ((sum p - 2) ^ k) / k! ... where there are \mjseqnk studies and the series continues until the numerator becomes negative \insertCiteedgington72ametap.

Some authors use a simpler version \mjdeqn\frac(\sum_i=1^k p_i)^kk!((sum p) ^ k) / k! but this can be very conservative when \mjeqn\sum_i=1^k p_i > 1sum p > 1. There seems no particular need to use this method but it is returned as the value of conservativep for use in checking published values.

\lele

two A warning is given when the internal calculations are likely to have been subject to numerical error and an alternative method should be used to check the result.

\plotmethod

### Value

An object of class ‘sump’ and ‘metap’, a list with entries

 p The transformed sum of the \mjseqnp-values conservativep See details validp The input vector with illegal values removed

Michael Dewey

### References

\insertAllCited

See also plotp
data(dat.metap)