\name{fitBumModel} \alias{fitBumModel} \title{ Fit beta-uniform mixture model to a p-value distribution } \description{ The function fits a beta-uniform mixture model to a given p-value distribution. The BUM method was introduced by Stan Pounds and Steve Morris to model the p-value distribution as a signal-noise decompostion. The signal component is assumed to be B(a,1)-distributed, whereas the noise component is uniform-distributed under the null hypothesis. } \usage{ fitBumModel(x, plot = TRUE, starts=10) } \arguments{ \item{x}{ Numeric vector of p-values. } \item{plot}{ Boolean value, whether to plot a histogram and qqplot of the p-values with the fitted model. } \item{starts}{ Numeric value giving the number of starts for the optimization. } } \value{ Maximum likelihood estimator object for the fitted bum model. List of class fb with the following elements: \item{lambda}{Fitted parameter \emph{lambda} for the beta-uniform mixture model.} \item{a}{Fitted parameter \emph{a} for the beta-uniform mixture model.} \item{negLL}{Negative log-likelihood.} \item{pvalues}{P-value vector.} } \references{ S. Pounds, S.W. Morris (2003) Estimating the occurrence of false positives and false negatives in microarray studies by approximating and partitioning the empirical distribution of p-values. \emph{Bioinformatics}, 19(10): 1236-1242. } \author{ Daniela Beisser } \examples{ data(pvaluesExample) pvals <- pvaluesExample[,1] bum.mle <- fitBumModel(pvals, plot=TRUE) bum.mle }