metap (version 1.1)

invchisq: Combine p values using inverse chi squared method

Description

Combine \(p\)-values by the inverse chi-squared method, also known as Lancaster's method,

Usage

invchisq(p, k, data = NULL, subset = NULL, na.action = na.fail)
# S3 method for invchisq
print(x, ...)

Arguments

p

A vector of significance values

k

A vector of degrees of freedom to use, see details

data

Optional data frame containing variables

subset

Optional vector of logicals to specify a subset of the \(p\)-values

na.action

A function indicating what should happen when data contains NAs

x

An object of class ‘invchisq’

...

Other arguments to be passed through

Value

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

chisq

Value of chi-squared statistic

df

Associated degrees of freedom

p

Associated p-value

validp

The input vector with the illegal values removed

Details

Defined as $$\sum_{i=1}^n \chi^2_{k_i}(p_i) > \chi^2_{\sum{k_i}}(\alpha)$$

If k is a single value it is used for all the p of which there are n. If any value of \(k_i<1\) then the corresponding \(p_i\) is not included.

The values of \(p_i\) should be such that \(0<p_i\le 1\) and a warning is given if that is not true. An error is given if, possibly as a result of removing illegal values, fewer than two values remain.

The plot method for class ‘metap’ calls plotp on the valid \(p\)-values. Inspection of the distribution of \(p\)-values is highly recommended as extreme values in opposite directions do not cancel out. See last example. This may not be what you want.

References

becker94metap

lancaster49metap

See Also

See also sumlog and plotp

Examples

# NOT RUN {
data(beckerp)
invchisq(beckerp, 2) # same as sumlog
invchisq(c(0.999, 0.999, 0.001, 0.001), 4)
# }