SKAT (version 2.2.5)

SKAT_NULL_emmaX: Get parameters and residuals from the null model with incorporating the kinship structure

Description

Compute model parameters and residuals for SKAT with incorporating the kinship structure.

Usage

SKAT_NULL_emmaX (formula, data=NULL, K=NULL, 
Kin.File=NULL, ngrids=100, llim=-10, ulim=10, esp=1e-10, Is.GetEigenResult=FALSE)

Value

This function returns an object that has model parameters and residuals of the NULL model of no associations. After obtaining it, use SKAT function to carry out the association test.

Arguments

formula

an object of class ``formula'': a symbolic description of the NULL model to be fitted.

data

an optional data frame containing the variables in the model (default=NULL). If it is NULL, the variables are taken from 'environment(formula)'

K

a kinship matrix. If K=NULL, the function reads Kin.File to get a kinship matrix.

Kin.File

an emmax-kin output file name. If K=NULL, the function reads this file.

ngrids

Number of grids to search for the optimal variance component

llim

Lower bound of log ratio of two variance components

ulim

Upper bound of log ratio of two variance components

esp

Tolerance of numerical precision error

Is.GetEigenResult

Return intermediate eigen-decomposition results

Author

Seunggeun Lee

Details

The Emma package code was used to implement this function.

Resampling is not implemented.

Examples

data(SKAT.fam.example)

K = SKAT.fam.example$K
Z = SKAT.fam.example$Z
obj<-SKAT_NULL_emmaX(y ~ X, K=K, data=SKAT.fam.example)
SKAT(Z, obj)$p.value

# SKAT-O
SKAT(Z, obj, method="optimal.adj")$p.value