addedges: no visible global function definition for 'par'
addedges: no visible global function definition for 'locator'
addedges: no visible global function definition for 'segments'
asgraph: no visible global function definition for 'dist'
checkmoves: no visible global function definition for 'dist'
deleteedges: no visible global function definition for 'par'
deleteedges: no visible global function definition for 'locator'
deleteedges: no visible global function definition for 'segments'
getLineID: no visible global function definition for 'locator'
getLineID: no visible global function definition for 'points'
getLineID: no visible global function definition for 'text'
make.line : alongline: no visible global function definition for
  'runif'
plot.linearmask: no visible global function definition for
  'terrain.colors'
plot.linearmask: no visible global function definition for 'text'
plot.linearpopn: no visible global function definition for 'runif'
rbind.linearmask : check: no visible global function definition for
  'is'
rbind.linearmask : <anonymous>: no visible global function definition
  for 'as'
read.linearmask: no visible global function definition for 'read.table'
read.linearmask: no visible global function definition for 'is'
replot: no visible global function definition for 'locator'
sample.line: no visible global function definition for 'is'
showedges: no visible global function definition for 'segments'
showpath: no visible global function definition for 'flush.console'
showpath: no visible global function definition for 'locator'
showpath: no visible global function definition for 'points'
showpath: no visible global function definition for 'lines'
showpath: no visible global function definition for 'dist'
Undefined global functions or variables:
  as dist flush.console is lines locator par points read.table runif
  segments terrain.colors text
Consider adding
  importFrom("grDevices", "terrain.colors")
  importFrom("graphics", "lines", "locator", "par", "points", "segments",
             "text")
  importFrom("methods", "as", "is")
  importFrom("stats", "dist", "runif")
  importFrom("utils", "flush.console", "read.table")
to your NAMESPACE file (and ensure that your DESCRIPTION Imports field
contains 'methods').