Compute the Inverse Square Root (Whitening Factor) of a Kinship Matrix

Returns \(A\) such that \(A V A^\top = I\). Used by prepare_geno when method = "rV2".

Usage

get_V_inv_sqrt(V, method = c("chol", "eigen"))

Arguments

V

Symmetric positive-definite matrix (n x n). Typically a VanRaden GRM after bending/tuning.

method

Character. "chol" (default, faster) or "eigen" (more robust for near-singular matrices).

Value

Numeric matrix A (n x n).