aoristic.all.graph: no visible global function definition for
  ‘aggregate’
aoristic.density: no visible global function definition for ‘as’
aoristic.density: no visible global function definition for
  ‘contourLines’
aoristic.density: no visible global function definition for ‘quantile’
aoristic.density: no visible global function definition for ‘aggregate’
aoristic.density: no visible global function definition for ‘slot’
aoristic.density : <anonymous>: no visible global function definition
  for ‘as’
aoristic.density : <anonymous>: no visible global function definition
  for ‘slot’
aoristic.density: no visible global function definition for ‘png’
aoristic.density: no visible global function definition for ‘par’
aoristic.density: no visible global function definition for
  ‘colorRampPalette’
aoristic.density: no visible global function definition for ‘image’
aoristic.density: no visible global function definition for ‘dev.off’
aoristic.density: no visible global function definition for ‘browseURL’
aoristic.grid: no visible global function definition for ‘as’
aoristic.grid: no visible global function definition for ‘aggregate’
aoristic.grid: no visible global function definition for ‘slot’
aoristic.grid : <anonymous>: no visible global function definition for
  ‘as’
aoristic.grid : <anonymous>: no visible global function definition for
  ‘slot’
aoristic.grid: no visible global function definition for ‘browseURL’
aoristic.shp: no visible global function definition for ‘aggregate’
aoristic.shp: no visible global function definition for ‘slot’
aoristic.shp : <anonymous>: no visible global function definition for
  ‘as’
aoristic.shp : <anonymous>: no visible global function definition for
  ‘slot’
aoristic.shp: no visible global function definition for ‘browseURL’
Undefined global functions or variables:
  aggregate as browseURL colorRampPalette contourLines dev.off image
  par png quantile slot
Consider adding
  importFrom("grDevices", "colorRampPalette", "contourLines", "dev.off",
             "png")
  importFrom("graphics", "image", "par")
  importFrom("methods", "as", "slot")
  importFrom("stats", "aggregate", "quantile")
  importFrom("utils", "browseURL")
to your NAMESPACE file (and ensure that your DESCRIPTION Imports field
contains 'methods').