eplot: no visible global function definition for ‘trellis.par.get’
eplot: no visible global function definition for ‘trellis.par.set’
eplot: no visible global function definition for ‘xyplot’
head.profile.data.frame: no visible global function definition for
  ‘head’
munsell_to_rgb: no visible global function definition for ‘munsell2rgb’
plot_profile: no visible global function definition for ‘aggregate’
plot_profile: no visible global function definition for ‘layout’
plot_profile: no visible global function definition for ‘lcm’
plot_profile: no visible global function definition for ‘par’
plot_profile: no visible global function definition for ‘plot’
plot_profile: no visible global function definition for ‘mtext’
plot_profile: no visible global function definition for ‘axis’
plot_profile: no visible global function definition for ‘rnorm’
plot_profile: no visible global function definition for ‘polygon’
plot_profile: no visible global function definition for ‘text’
plot_profile: no visible global function definition for ‘lines’
plot_profile: no visible global function definition for ‘legend’
retrieve.horizons: no visible global function definition for ‘polygon’
retrieve.roots: no visible global function definition for ‘polygon’
retrieve.skeletal: no visible global function definition for ‘polygon’
roots: no visible global function definition for ‘areapl’
roots: no visible global function definition for ‘runif’
roots: no visible global function definition for ‘point.in.polygon’
roots: no visible global function definition for ‘na.omit’
roots: no visible global function definition for ‘polygon’
skeletal: no visible global function definition for ‘areapl’
skeletal: no visible global function definition for ‘runif’
skeletal: no visible global function definition for ‘point.in.polygon’
skeletal: no visible global function definition for ‘polygon’
tail.profile.data.frame: no visible global function definition for
  ‘tail’
Undefined global functions or variables:
  aggregate areapl axis head layout lcm legend lines mtext munsell2rgb
  na.omit par plot point.in.polygon polygon rnorm runif tail text
  trellis.par.get trellis.par.set xyplot
Consider adding
  importFrom("graphics", "axis", "layout", "lcm", "legend", "lines",
             "mtext", "par", "plot", "polygon", "text")
  importFrom("stats", "aggregate", "na.omit", "rnorm", "runif")
  importFrom("utils", "head", "tail")
to your NAMESPACE file.