This vignette .. brief introduction ….
What do I want to include in here? Demonstrate example how to use mr_simss and also est_lambda
First create a toy data set…
Establish function to create toy data set.. specify certain parameters etc….??
mr_simssAfter toy data set is made, we can now consider applying method … detailed discussion of how to do that and the various options included …
est_lambdaAs well as estimates of the variant-exposure and variant-outcome
associations and corresponding standard errors, the method also requires
(a) knowledge of the number of samples in both outcome and
exposure GWASs, the number of overlapping samples between the two GWASs,
and the correlation between the exposure and the outcome, or
(b) an estimate of the correlation between the SNP-outcome and
SNP-exposure effect sizes. Due to this, this R package also contains a
supplementary function,
est_lambda, which allows users to obtain an
unbiased estimate for lambda, the correlation between
the variant-outcome and variant-exposure effect sizes, using a
conditional log-likelihood approach. It is recommended to use this
function when the fraction of overlap and the correlation between
exposure and outcome are unknown. Merely the GWAS summary
statistics of a large set of unpruned variants or
single nucleotide polymorphisms (SNPs) are required in order to obtain
an estimate for lambda.
Important to have a section on Runtime here…