krigr_cross_validation
                        Multithreaded cross validation routine for Omic
                        Kriging.
load_sample_data        Loads sample phenotype and covariate data into
                        data frame.
make_GXM                Compute gene expression correlation matrix.
make_PCs_irlba          Run Principal Component Analysis (PCA) using
                        the irlba package.
make_PCs_svd            Run Principal Component Analysis (PCA) using
                        base R svd() function.
okriging                Run omic kriging on a set of correlation
                        matrices and a given phenotype.
read_GRMBin             Read the GRM binary file.
write_GRMBin            Write GRM binary files.
