generateSNPs : sim.block: no visible global function definition for
  ‘rbinom’
generateSNPs : <anonymous>: no visible global function definition for
  ‘rbinom’
minPtest: no visible global function definition for ‘sfIsRunning’
minPtest: no visible global function definition for ‘sfInit’
minPtest: no visible global function definition for ‘sfLibrary’
minPtest: no visible global function definition for ‘sfExport’
minPtest : p_valfunc: no visible global function definition for
  ‘as.formula’
minPtest : p_valfunc: no visible global function definition for ‘glm’
minPtest : p_valfunc: no visible binding for global variable ‘binomial’
minPtest : perrfunc : <anonymous>: no visible global function
  definition for ‘as.formula’
minPtest : perrfunc : <anonymous>: no visible global function
  definition for ‘glm’
minPtest : perrfunc : <anonymous>: no visible binding for global
  variable ‘binomial’
minPtest : p_valfunc: no visible global function definition for
  ‘pchisq’
minPtest : perrfunc : <anonymous>: no visible global function
  definition for ‘pchisq’
minPtest: no visible global function definition for ‘sfClusterApplyLB’
minPtest: no visible global function definition for ‘mclapply’
minPtest: no visible global function definition for ‘sfStop’
minPtest: no visible global function definition for ‘p.adjust’
plot.minPtest: no visible global function definition for ‘plot’
plot.minPtest: no visible global function definition for ‘points’
plot.minPtest: no visible global function definition for ‘axis’
plot.minPtest: no visible global function definition for ‘box’
plot.minPtest: no visible global function definition for ‘median’
plot.minPtest: no visible global function definition for ‘par’
plot.minPtest: no visible global function definition for ‘lines’
plot.minPtest: no visible global function definition for ‘mtext’
Undefined global functions or variables:
  as.formula axis binomial box glm lines mclapply median mtext p.adjust
  par pchisq plot points rbinom sfClusterApplyLB sfExport sfInit
  sfIsRunning sfLibrary sfStop
Consider adding
  importFrom("graphics", "axis", "box", "lines", "mtext", "par", "plot",
             "points")
  importFrom("stats", "as.formula", "binomial", "glm", "median",
             "p.adjust", "pchisq", "rbinom")
to your NAMESPACE file.