f.Q: Compute Cochran's Q statistic

Description Usage Arguments Details Value Author(s) References See Also Examples

View source: R/meta1.R


Compute Cochran's Q statistic for testing whether the a fixed effects or a random effects model will be appropriate.


f.Q(dadj, varadj)



A matrix, each row is a gene, each column a study, of the estimated t-statistics.


A matrix, each row is a gene, each column a study, of the estimated, adjusted variances of the t-statistics.


A straightforward computation of Cochran's Q statistic. If the null hypothesis that the data are well modeled by a fixed effects design is true then the estimate Q values will have approximately a chi-squared distribution with degrees of freedom equal to the number of studies minus one.


A vector of length equal to the number of rows of dadj with the Q statistics.


L. Lusa and R. Gentleman


Choi et al, Combining multiple microarray studies and modeling interstudy variation. Bioinformatics, 2003, i84-i90.

See Also



##none now, this requires a pretty elaborate example

Example output

Loading required package: Biobase
Loading required package: BiocGenerics
Loading required package: parallel

Attaching package: 'BiocGenerics'

The following objects are masked from 'package:parallel':

    clusterApply, clusterApplyLB, clusterCall, clusterEvalQ,
    clusterExport, clusterMap, parApply, parCapply, parLapply,
    parLapplyLB, parRapply, parSapply, parSapplyLB

The following objects are masked from 'package:stats':

    IQR, mad, sd, var, xtabs

The following objects are masked from 'package:base':

    Filter, Find, Map, Position, Reduce, anyDuplicated, append,
    as.data.frame, cbind, colMeans, colSums, colnames, do.call,
    duplicated, eval, evalq, get, grep, grepl, intersect, is.unsorted,
    lapply, lengths, mapply, match, mget, order, paste, pmax, pmax.int,
    pmin, pmin.int, rank, rbind, rowMeans, rowSums, rownames, sapply,
    setdiff, sort, table, tapply, union, unique, unsplit, which,
    which.max, which.min

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    'browseVignettes()'. To cite Bioconductor, see
    'citation("Biobase")', and for packages 'citation("pkgname")'.

Loading required package: genefilter

GeneMeta documentation built on Nov. 8, 2020, 7:58 p.m.