import(MASS, survey)
export(svycollinear, svyCooksD, svydfbetas, svydffits, svyhat, svystdres, svyvif, Vmat)
importFrom("graphics", "abline", "plot")
importFrom("stats", "glm.fit", "model.matrix", "predict", "var", "vcov", "weighted.mean")
importFrom("utils", "head")
importFrom("Matrix", "bdiag") 