Testing_coefficient_of_mediator {SMUT}

Testing coefficient of mediator in the outcome model

Description

Testing coefficient of mediator, namely theta, in the outcome model. The outcome model is the following.
outcome ~ intercept + G*gamma + mediator*theta + error

Usage

Testing_coefficient_of_mediator(G, mediator, outcome, 
outcome_type="continuous", method="score", approxi=TRUE, debug=FALSE)

Arguments

G

n by p matrix (n rows and p columns). Each row is one individual; each column is one SNP.

mediator

a vector length of n. It is the mediator variable.

outcome

a vector length of n. It is the outcome variable.

outcome_type

Type of the outcome variable. For now, this package only deals with continuous outcome. Default is "continuous".

method

The method of testing coefficient of mediator in the outcome model. The score test is used. Default is "score".

approxi

a boolean value. This is an indicator whether the approximation of the score statistic is applied to save computing time. Default is TRUE.

debug

a boolean value. If TRUE a lot of computing details is printed; otherwise the function is completely silent. Default is FALSE.

Value

P value for testing the coefficient of mediator in the outcome model.

Author(s)

Wujuan Zhong

Examples

library(SMUT)
# load the Genotype data included in this R package
data("Genotype_data")

# generate one mediator and one outcome

set.seed(1)
beta=rnorm(ncol(Genotype_data),1,2)
e1 = rnorm(nrow(Genotype_data), 0, 1)
mediator = 1 + eigenMapMatMult(Genotype_data,beta) + e1

theta=0.8
gamma=rnorm(ncol(Genotype_data),0.5,2)
e2 = rnorm(nrow(Genotype_data), 0, 1)
outcome = 2 + eigenMapMatMult(Genotype_data,gamma) + theta*mediator + e2

p_value=Testing_coefficient_of_mediator(G=Genotype_data,mediator=mediator,outcome=outcome)
print(p_value)

# Thanks for using our R package SMUT