.onAttach: no visible global function definition for
  ‘packageDescription’
anchors: no visible binding for global variable ‘na.omit’
anchors.chopit.fit : chopit.llog: no visible global function definition
  for ‘Rprof’
anchors.chopit.fit: no visible global function definition for ‘optim’
anchors.combn: no visible global function definition for ‘as.formula’
anchors.combn: no visible global function definition for ‘combn’
anchors.data: no visible binding for global variable ‘na.omit’
anchors.data: no visible global function definition for ‘as.formula’
anchors.data: no visible global function definition for ‘model.frame’
anchors.data: no visible global function definition for ‘model.matrix’
anchors.data: no visible global function definition for
  ‘model.response’
anchors.order: no visible binding for global variable ‘na.omit’
anchors.order.calc: no visible global function definition for ‘runif’
anchors.rank: no visible global function definition for ‘as.formula’
chopit: no visible binding for global variable ‘na.omit’
convert: no visible global function definition for ‘na.omit’
cpolr: no visible binding for global variable ‘plogis’
cpolr: no visible binding for global variable ‘pnorm’
cpolr: no visible binding for global variable ‘dlogis’
cpolr: no visible binding for global variable ‘dnorm’
cpolr: no visible global function definition for ‘model.matrix’
cpolr: no visible global function definition for ‘model.weights’
cpolr: no visible global function definition for ‘model.offset’
cpolr: no visible global function definition for ‘model.response’
cpolr: no visible global function definition for ‘glm.fit’
cpolr: no visible global function definition for ‘binomial’
cpolr: no visible global function definition for ‘optim’
cpolr: no visible global function definition for ‘.getXlevels’
fitted.anchors.rank: no visible global function definition for ‘fitted’
gr.oprobit.self: no visible global function definition for ‘pnorm’
gr.oprobit.self: no visible global function definition for ‘dnorm’
gr.oprobit.vign: no visible global function definition for ‘pnorm’
gr.oprobit.vign: no visible global function definition for ‘dnorm’
ll.oprobit.unim: no visible global function definition for ‘pnorm’
ll.self.ai : f: no visible global function definition for ‘dnorm’
ll.self.ai: no visible global function definition for ‘integrate’
ll.self.ai.prob: no visible global function definition for ‘pnorm’
plot.anchors.combn: no visible global function definition for ‘na.omit’
summary.anchors.order: no visible global function definition for
  ‘xtabs’
summary.anchors.rank: no visible global function definition for
  ‘fitted’
vcov.cpolr: no visible binding for global variable ‘flush.console’
vcov.cpolr: no visible global function definition for ‘update’
Undefined global functions or variables:
  .getXlevels Rprof as.formula binomial combn dlogis dnorm fitted
  flush.console glm.fit integrate model.frame model.matrix model.offset
  model.response model.weights na.omit optim packageDescription plogis
  pnorm runif update xtabs
Consider adding
  importFrom("stats", ".getXlevels", "as.formula", "binomial", "dlogis",
             "dnorm", "fitted", "glm.fit", "integrate", "model.frame",
             "model.matrix", "model.offset", "model.response",
             "model.weights", "na.omit", "optim", "plogis", "pnorm",
             "runif", "update", "xtabs")
  importFrom("utils", "Rprof", "combn", "flush.console",
             "packageDescription")
to your NAMESPACE file.