Emp.variog: no visible global function definition for 'lm'
Emp.variog: no visible global function definition for 'var'
Emp.variog: no visible binding for global variable 'median'
Emp.variog: no visible global function definition for 'quantile'
EmpDir.variog: no visible global function definition for 'lm'
EmpDir.variog: no visible global function definition for 'var'
EmpDir.variog: no visible binding for global variable 'median'
EmpDir.variog: no visible global function definition for 'quantile'
Field.sim: no visible global function definition for 'lm'
Field.sim: no visible global function definition for 'qnorm'
Field.sim: no visible global function definition for 'par'
ProbForecastGOP: no visible global function definition for 'lm'
ProbForecastGOP: no visible global function definition for 'var'
ProbForecastGOP: no visible binding for global variable 'median'
ProbForecastGOP: no visible global function definition for 'quantile'
ProbForecastGOP: no visible global function definition for 'qnorm'
ProbForecastGOP: no visible global function definition for 'par'
avg.variog: no visible global function definition for 'var'
avg.variog: no visible binding for global variable 'median'
avg.variog: no visible global function definition for 'quantile'
avg.variog.dir: no visible binding for global variable 'median'
avg.variog.dir: no visible global function definition for 'quantile'
ens.plot: no visible global function definition for 'rainbow'
model.fit: no visible global function definition for 'lowess'
model.fit: no visible global function definition for 'optim'
plotfields: no visible global function definition for 'par'
plotfields: no visible global function definition for 'rainbow'
Undefined global functions or variables:
  lm lowess median optim par qnorm quantile rainbow var
Consider adding
  importFrom("grDevices", "rainbow")
  importFrom("graphics", "par")
  importFrom("stats", "lm", "lowess", "median", "optim", "qnorm",
             "quantile", "var")
to your NAMESPACE file.