invt {metap}

Combine p values using the inverse t method

Description

Combine p values using the inverse t method

Usage

invt(p, k, data = NULL, subset = NULL, na.action = na.fail,
   log.p = FALSE)
## S3 method for class 'invt'
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

log.p

Logical, if TRUE result is returned as log(p)

x

An object of class ‘invt’

...

Other arguments to be passed through

Details

Defined as \[\frac{\sum_{i=1}^n t_{k_i}(p_i)} {\sqrt{\sum_{i=1}^n \frac{k_i}{k_i - 2}}} > z(\alpha) \]

If k is a single value it is used for all the p of which there are n. If any value of \(k_i\le2\) 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. A warning is given if, possibly as a result of removing illegal values, fewer than two values remain and the return values are set to NA.

The plot method for class ‘metap’ calls plotp on the valid p-values.

Value

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

z

Value of z

p

Associated p-value

validp

The input vector with the illegal values removed

Author(s)

Michael Dewey

References

Becker BJ (1994). “Combining significance levels.” In Cooper H, Hedges LV (eds.), A handbook of research synthesis, 215–230. Russell Sage, New York.

See Also

See also plotp

Examples

data(dat.metap)
beckerp <- dat.metap$beckerp
invt(beckerp, 50)
all.equal(exp(invt(beckerp, 50, log.p = TRUE)$p), invt(beckerp, 50)$p)