vc_score: Computes variance component test statistic for longitudinal

In dearseq: Differential Expression Analysis for RNA-seq data through a robust variance component test

Description

This function computes an approximation of the Variance Component test for a mixture of χ^{2}s using Davies method from davies

Usage

vc_score(y, x, indiv, phi, w, Sigma_xi = diag(ncol(phi)), na_rm = FALSE)

Arguments

y	a numeric matrix of dim g x n containing the raw RNA-seq counts for g genes from n samples
x	a numeric design matrix of dim n x p containing the p covariates to be adjusted for
indiv	a vector of length n containing the information for attributing each sample to one of the studied individuals. Coerced to be a factor
phi	a numeric design matrix of size n x K containing the K variables to be tested
w	a vector of length n containing the weights for the n samples.
Sigma_xi	a matrix of size K x K containing the covariance matrix of the K random effects on phi
na_rm	logical: should missing values (including NA and NaN) be omitted from the calculations? Default is FALSE.

Value

A list with the following elements:

• score: approximation of the set observed score

• q: observation-level contributions to the score

• q_ext: pseudo-observations used to compute the covariance, taking into account the contributions of OLS estimates

• gene_scores_unscaled: a vector of the approximations of the individual gene scores

See Also

davies

Examples

set.seed(123)

##generate some fake data
########################
n <- 100
r <- 12
t <- matrix(rep(1:3), r/3, ncol=1, nrow=r)
sigma <- 0.4
b0 <- 1

#under the null:
b1 <- 0
#under the alternative:
b1 <- 0.7
y.tilde <- b0 + b1*t + rnorm(r, sd = sigma)
y <- t(matrix(rnorm(n*r, sd = sqrt(sigma*abs(y.tilde))), ncol=n, nrow=r) +
      matrix(rep(y.tilde, n), ncol=n, nrow=r))
x <- matrix(1, ncol=1, nrow=r)

#run test
scoreTest <- vc_score(y, x, phi=t, w=matrix(1, ncol=ncol(y), nrow=nrow(y)),
                    Sigma_xi=matrix(1), indiv=rep(1:(r/3), each=3))
scoreTest$score

dearseq documentation built on Nov. 8, 2020, 5:49 p.m.