BFD_Processor: no visible global function definition for ‘read.table’
BFD_Processor: no visible global function definition for ‘write.table’
BFD_Processor: no visible global function definition for ‘png’
BFD_Processor: no visible global function definition for ‘dev.off’
BFD_Processor: no visible global function definition for ‘read.delim’
BFD_Processor: no visible global function definition for ‘pdf’
BFD_Processor: no visible global function definition for ‘levelplot’
BFD_Processor: no visible global function definition for ‘heatmap’
BFD_Processor: no visible global function definition for ‘cor’
BFD_Processor: no visible global function definition for ‘corrplot’
DEGREE_MEASURE: no visible global function definition for ‘write.table’
Exhaustive_double_deletion: no visible global function definition for
  ‘combn’
Exhaustive_double_deletion: no visible global function definition for
  ‘write.table’
Exhaustive_single_deletion: no visible global function definition for
  ‘write.table’
Exhaustive_single_deletion: no visible global function definition for
  ‘hist’
Exhaustive_single_deletion: no visible global function definition for
  ‘pdf’
Exhaustive_single_deletion: no visible global function definition for
  ‘barplot’
Exhaustive_single_deletion: no visible global function definition for
  ‘dev.off’
FBA_solve: no visible global function definition for ‘Rglpk_solve_LP’
FLUX_VAR_ANALYSIS: no visible global function definition for
  ‘write.table’
PERTURBATION_analysis: no visible global function definition for ‘png’
PERTURBATION_analysis: no visible global function definition for
  ‘dev.off’
PERTURBATION_analysis: no visible global function definition for
  ‘write.table’
PHPP: no visible global function definition for ‘levelplot’
PHPP: no visible global function definition for ‘persp3d’
PHPP: no visible global function definition for ‘play3d’
PHPP: no visible global function definition for ‘spin3d’
PLOT_FVA_SPAN: no visible global function definition for ‘pdf’
PLOT_FVA_SPAN: no visible global function definition for ‘barplot’
PLOT_FVA_SPAN: no visible global function definition for ‘par’
PLOT_FVA_SPAN: no visible global function definition for ‘dev.off’
SINGLE_DEL_FLUXOME: no visible global function definition for ‘pdf’
SINGLE_DEL_FLUXOME: no visible global function definition for ‘barplot’
SINGLE_DEL_FLUXOME: no visible global function definition for ‘par’
SINGLE_DEL_FLUXOME: no visible global function definition for ‘dev.off’
flux_difference_plotter: no visible global function definition for
  ‘pdf’
flux_difference_plotter: no visible global function definition for
  ‘barplot’
flux_difference_plotter: no visible global function definition for
  ‘par’
flux_difference_plotter: no visible global function definition for
  ‘dev.off’
Undefined global functions or variables:
  Rglpk_solve_LP barplot combn cor corrplot dev.off heatmap hist
  levelplot par pdf persp3d play3d png read.delim read.table spin3d
  write.table
Consider adding
  importFrom("grDevices", "dev.off", "pdf", "png")
  importFrom("graphics", "barplot", "hist", "par")
  importFrom("stats", "cor", "heatmap")
  importFrom("utils", "combn", "read.delim", "read.table", "write.table")
to your NAMESPACE file.