autoplot.microbenchmark: no visible global function definition for
  'ggplot'
autoplot.microbenchmark: no visible global function definition for
  'aes'
autoplot.microbenchmark: no visible global function definition for
  'coord_cartesian'
autoplot.microbenchmark: no visible global function definition for
  'stat_summary'
autoplot.microbenchmark: no visible global function definition for
  'opts'
autoplot.microbenchmark: no visible global function definition for
  'theme_text'
compareplot: no visible global function definition for 'grid.newpage'
compareplot: no visible global function definition for
  'latticeParseFormula'
compareplot: no visible global function definition for 'pushViewport'
compareplot: no visible global function definition for 'viewport'
compareplot: no visible global function definition for 'grid.layout'
compareplot: no visible global function definition for 'unit'
compareplot: no visible global function definition for 'seekViewport'
compareplot: no visible global function definition for 'grid.rect'
compareplot : makeNat: no visible global function definition for
  'convertUnit'
compareplot: no visible global function definition for 'grid.text'
compareplot: no visible global function definition for 'gpar'
compareplot: no visible global function definition for 'grid.lines'
compareplot: no visible global function definition for 'grid.points'
compareplot: no visible global function definition for 'grid.polyline'
compareplot: no visible global function definition for 'upViewport'
compareplot: no visible global function definition for 'convertUnit'
compareplot: no visible global function definition for 'popViewport'
hist_horiz: no visible global function definition for
  'latticeParseFormula'
latex.table.by: no visible global function definition for 'xtable'
panel.densityplot.enhanced: no visible global function definition for
  'panel.densityplot'
panel.densityplot.enhanced: no visible global function definition for
  'unit'
panel.densityplot.enhanced: no visible global function definition for
  'grid.text'
panel.densityplot.enhanced: no visible global function definition for
  'gpar'
panel.ecdf: no visible global function definition for 'panel.xyplot'
panel.ecdf: no visible global function definition for 'panel.lines'
panel.xyplot_rug: no visible global function definition for
  'panel.xyplot'
panel.xyplot_rug: no visible global function definition for
  'grid.segments'
panel.xyplot_rug: no visible global function definition for 'unit'
panel.xyplot_rug: no visible global function definition for 'gpar'
searchPattern: no visible global function definition for 'interleave'
xtable.CrossTable: no visible global function definition for
  'caption<-'
xtable.CrossTable: no visible global function definition for 'label<-'
xtable.CrossTable: no visible global function definition for 'align<-'
xtable.CrossTable: no visible global function definition for 'digits<-'
xtable.CrossTable: no visible global function definition for
  'display<-'
xtable.summary.lme: no visible global function definition for
  'caption<-'
xtable.summary.lme: no visible global function definition for 'label<-'
xtable.summary.lme: no visible global function definition for 'align<-'
xtable.summary.lme: no visible global function definition for
  'digits<-'
xtable.summary.lme: no visible global function definition for
  'display<-'
xtablelm: no visible global function definition for 'xtable'
Undefined global functions or variables:
  aes align<- caption<- convertUnit coord_cartesian digits<- display<-
  ggplot gpar grid.layout grid.lines grid.newpage grid.points
  grid.polyline grid.rect grid.segments grid.text interleave label<-
  latticeParseFormula opts panel.densityplot panel.lines panel.xyplot
  popViewport pushViewport seekViewport stat_summary theme_text unit
  upViewport viewport xtable