em: no visible global function definition for ‘optim’
em.m: no visible global function definition for ‘optim’
fitmix: no visible global function definition for ‘model.matrix’
fitmix: no visible global function definition for ‘as.formula’
fitmix: no visible global function definition for ‘optim’
flt.gr : Af: no visible global function definition for ‘dgamma’
integrate.hn: no visible global function definition for ‘pnorm’
inv.reparam.pi : F: no visible global function definition for ‘pgamma’
inv.reparam.pi : Finv: no visible global function definition for
  ‘qgamma’
plot.ds.mixture: no visible global function definition for ‘hist’
plot.ds.mixture: no visible global function definition for ‘par’
plot.ds.mixture: no visible global function definition for ‘plot’
plot.ds.mixture: no visible global function definition for ‘axis’
plot.ds.mixture: no visible global function definition for ‘lines’
plot.ds.mixture: no visible global function definition for ‘box’
plot.ds.mixture: no visible global function definition for ‘as.formula’
plot.ds.mixture: no visible global function definition for
  ‘terms.formula’
plot.ds.mixture: no visible global function definition for ‘quantile’
plot.ds.mixture: no visible global function definition for ‘grey’
reparam.pi : F: no visible global function definition for ‘pgamma’
setinitialvalues: no visible global function definition for ‘lm’
setinitialvalues: no visible global function definition for
  ‘as.formula’
sim.mix: no visible global function definition for ‘runif’
sim.mix: no visible global function definition for ‘optimize’
Undefined global functions or variables:
  as.formula axis box dgamma grey hist lines lm model.matrix optim
  optimize par pgamma plot pnorm qgamma quantile runif terms.formula
Consider adding
  importFrom("grDevices", "grey")
  importFrom("graphics", "axis", "box", "hist", "lines", "par", "plot")
  importFrom("stats", "as.formula", "dgamma", "lm", "model.matrix",
             "optim", "optimize", "pgamma", "pnorm", "qgamma",
             "quantile", "runif", "terms.formula")
to your NAMESPACE file.