checkdata               A function used to check the core inputs of
                        function glide
glide                   Evaluate individual and global pleiotropy among
                        genotypes being used as instrumental variables
                        in Mendelian randomization studies.
plot.egger              A function used to draw Egger plot
plot.glide              A function used to draw the q-q plot
remove_missingdata      A function used to remove missing data
simdata                 An example dataset to demonstrate the usage of
                        GLIDE
