snpcov_mvmr: snpcov_mvmr

In WSpiller/MRPracticals: An R Package illustrating features of MR Base and RadialMR

Description

Uses individual level genetic and exposure data to generate covariance matrices for estimated effects of individual genetic variants on each exposure. The function returns a number of covariance matrices equal to the number of SNPs, where SNP and row numbers reference ordered exposures.

Usage

snpcov_mvmr(Gs, Xs)

Arguments

Gs	A matrix or dataframe containing genetic instrument measures. Columns should indicate genetic variant number, with rows representing an observed measure of the genetic variant.
Xs	A matrix or dataframe containing exposure measures. Columns should indicate exposure number, with rows representing an observed measure for the given exposure.

Value

A list of covariance matrices with respect to each genetic variant, retaining the ordering in Gs

Author(s)

Wes Spiller; Eleanor Sanderson; Jack Bowden.

References

Sanderson, E., et al., An examination of multivariable Mendelian randomization in the single-sample and two-sample summary data settings. International Journal of Epidemiology, 2018. [Internet]. 2018;dyy262. Available from: https://dx.doi.org/10.1093/ije/dyy262

Examples

snpcov_mvmr(data[,1:10],data[,11:13])

WSpiller/MRPracticals documentation built on April 25, 2020, 10:52 a.m.