Hi, Is there an implementation of Fisher's method of combining p-values available as a part of package ? thanks, lau [[alternative HTML version deleted]]

The statistics from Fisher's method simply sums up the p-values on log scale across the studies and multiplied by minus two. Under the null hypothesis, this follows a chisquare distribution with degrees of freedom equivalent to twice the number of studies. If you store the p-values from different studies as columns in 'pvalues.mat' where the rows are genes. Then if I remember my arithmethics correctly you have stats <- rowSums( -2*log( pvalues.mat ), na.rm=T ) Npresent <- rowSums( !is.na(pvalues.mat) ) pval <- pchisq( stats, df=2*Npresent, lower=FALSE ) Please double check. Regards, Adai Laura wrote: > Hi, > Is there an implementation of Fisher's method of combining p-values > available as a part of package ? > > thanks, > lau > > [[alternative HTML version deleted]] > > _______________________________________________ > Bioconductor mailing list > Bioconductor at stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/bioconductor > Search the archives: http://news.gmane.org/gmane.science.biology.informatics.conductor