calc_k : perform_calc: no visible global function definition for 'dist'
calc_k : perform_calc: no visible global function definition for 'cor'
calc_k: no visible global function definition for 'par'
calc_k: no visible global function definition for 'abline'
calc_k: no visible global function definition for 'grid'
calc_k: no visible global function definition for 'head'
find_nn_eps: no visible global function definition for 'dist'
find_nn_k: no visible global function definition for 'dist'
find_weights: no visible global function definition for 'head'
find_weights: no visible global function definition for 'ecdf'
lle_rectangular : rects: no visible global function definition for
  'head'
lle_rectangular : rects: no visible global function definition for
  'rnorm'
lle_scurve: no visible global function definition for 'rnorm'
lle_scurve: no visible global function definition for 'runif'
lle_sound: no visible global function definition for 'data'
lle_sound: no visible binding for global variable 'lle_wave'
lle_sound: no visible global function definition for 'lines'
lle_sound: no visible global function definition for 'smooth.spline'
lle_spiral: no visible global function definition for 'split.screen'
lle_spiral: no visible global function definition for 'rnorm'
lle_spiral: no visible global function definition for 'screen'
lle_spiral: no visible global function definition for 'text'
lle_swissrole: no visible global function definition for 'runif'
plot_lle: no visible global function definition for 'plot3d'
plot_lle: no visible global function definition for 'palette'
plot_lle: no visible global function definition for 'rainbow'
plot_lle: no visible global function definition for 'pdf'
plot_lle: no visible global function definition for 'dev.new'
plot_lle: no visible global function definition for 'split.screen'
plot_lle: no visible global function definition for 'screen'
plot_lle: no visible global function definition for 'text'
plot_lle: no visible global function definition for 'dev.off'
Undefined global functions or variables:
  abline cor data dev.new dev.off dist ecdf grid head lines lle_wave
  palette par pdf plot3d rainbow rnorm runif screen smooth.spline
  split.screen text
Consider adding
  importFrom("grDevices", "dev.new", "dev.off", "palette", "pdf",
             "rainbow")
  importFrom("graphics", "abline", "grid", "lines", "par", "screen",
             "split.screen", "text")
  importFrom("stats", "cor", "dist", "ecdf", "rnorm", "runif",
             "smooth.spline")
  importFrom("utils", "data", "head")
to your NAMESPACE file.