calcPeriods: no visible global function definition for 'frequency'
plotRsdAcfGUI: no visible global function definition for 'frequency'
plotRsdAcfGUI: no visible global function definition for 'axis'
plotRsdAcfGUI: no visible global function definition for 'abline'
plotRsdAcfGUI: no visible global function definition for 'lines'
plotRsdAcfGUI: no visible global function definition for 'text'
plotgui: no visible global function definition for 'frequency'
plotgui: no visible global function definition for 'axTicks'
plotgui: no visible global function definition for 'axis'
plotgui: no visible global function definition for 'lines'
plotgui: no visible global function definition for 'time'
plotgui: no visible global function definition for 'polygon'
plotgui: no visible global function definition for 'window'
plotgui: no visible global function definition for 'end'
plotgui: no visible global function definition for 'abline'
plotgui: no visible global function definition for 'tsp'
plotgui : <anonymous>: no visible global function definition for
  'window'
plotgui: no visible global function definition for 'points'
plotgui: no visible global function definition for 'na.omit'
putKey.New: no visible global function definition for 'par'
putKeyEmpty.New: no visible global function definition for 'par'
x12GUI : checkbuttonx12handler: no visible global function definition
  for 'capture.output'
x12GUI : tablehandler: no visible global function definition for
  'capture.output'
x12GUI : convertCoordinates: no visible global function definition for
  'par'
x12GUI : convertCoordinates: no visible global function definition for
  'frequency'
x12GUI : convertCoordinates: no visible global function definition for
  'end'
x12GUI : convertCoordinates: no visible global function definition for
  'start'
x12GUI : update_notebook: no visible global function definition for
  'dev.cur'
x12GUI : update_notebook: no visible global function definition for
  'dev.set'
x12GUI : menuhandler: no visible global function definition for
  'dev.cur'
x12GUI : menuhandler: no visible global function definition for 'pdf'
x12GUI : menuhandler: no visible global function definition for
  'dev.off'
x12GUI : menuhandler: no visible global function definition for
  'dev.set'
x12GUI : menuhandler: no visible global function definition for 'png'
x12GUI : menuhandler: no visible global function definition for 'end'
x12GUI : menuhandler: no visible global function definition for 'start'
x12GUI : menuhandler: no visible global function definition for
  'write.csv2'
x12GUI : menuhandler: no visible global function definition for
  'capture.output'
x12GUI : make_summary: no visible global function definition for
  'capture.output'
x12GUI : make_plot: no visible global function definition for
  'capture.output'
x12GUI : make_plot: no visible global function definition for
  'frequency'
x12GUI : make_plot: no visible global function definition for 'start'
x12GUI : make_plot: no visible global function definition for 'end'
x12GUI : calcSpan: no visible global function definition for
  'frequency'
x12GUI : <anonymous>: no visible global function definition for
  'capture.output'
x12GUI: no visible global function definition for 'capture.output'
Undefined global functions or variables:
  abline axTicks axis capture.output dev.cur dev.off dev.set end
  frequency lines na.omit par pdf png points polygon start text time
  tsp window write.csv2
Consider adding
  importFrom("grDevices", "dev.cur", "dev.off", "dev.set", "pdf", "png")
  importFrom("graphics", "abline", "axTicks", "axis", "lines", "par",
             "points", "polygon", "text")
  importFrom("stats", "end", "frequency", "na.omit", "start", "time",
             "tsp", "window")
  importFrom("utils", "capture.output", "write.csv2")
to your NAMESPACE file.