.add.states: no visible global function definition for ‘rect’
.add.states: no visible global function definition for ‘axTicks’
.add.states: no visible global function definition for ‘legend’
.build_d: no visible global function definition for ‘dlnorm’
.build_d: no visible global function definition for ‘dgamma’
.build_d: no visible global function definition for ‘head’
.dnbinom.hsmm.sojourn: no visible global function definition for
  ‘dnbinom’
.dpois.hsmm.sojourn: no visible global function definition for ‘dpois’
.fitnbinom: no visible global function definition for ‘tail’
.fitnbinom : fun1: no visible global function definition for
  ‘weighted.mean’
.fitnbinom : fun1: no visible global function definition for ‘cov.wt’
.fitnbinom : fun1 : densfun: no visible global function definition for
  ‘dnbinom’
.fitnbinom : fun1: no visible global function definition for ‘optim’
.fitnbinom: no visible global function definition for ‘weighted.mean’
.fitnbinom: no visible global function definition for ‘cov.wt’
.fitnbinom : densfun: no visible global function definition for
  ‘dnbinom’
.fitnbinom: no visible global function definition for ‘optim’
.logdistrfit: no visible global function definition for ‘uniroot’
.rnbinom.hsmm.sojourn: no visible global function definition for
  ‘rnbinom’
.rpois.hsmm.sojourn: no visible global function definition for ‘rpois’
.sim.mhsmm: no visible global function definition for ‘dgamma’
.sim.mhsmm: no visible global function definition for ‘dlnorm’
addStates: no visible global function definition for ‘axTicks’
addStates : draw.it: no visible global function definition for ‘rect’
addStates: no visible global function definition for ‘legend’
dnorm.hsmm: no visible global function definition for ‘dnorm’
dpois.hsmm: no visible global function definition for ‘dpois’
gammafit: no visible global function definition for ‘cov.wt’
gammafit: no visible global function definition for ‘weighted.mean’
hsmmfit: no visible global function definition for ‘approx’
hsmmfit: no visible global function definition for ‘density’
hsmmfit: no visible global function definition for ‘tail’
hsmmfit: no visible global function definition for ‘dgamma’
hsmmfit: no visible global function definition for ‘weighted.mean’
hsmmfit: no visible global function definition for ‘cov.wt’
hsmmfit: no visible global function definition for ‘dlnorm’
mstep.mvnorm: no visible global function definition for ‘cov.wt’
mstep.norm: no visible global function definition for ‘cov.wt’
mstep.pois: no visible global function definition for ‘weighted.mean’
plot.hsmm: no visible global function definition for ‘plot’
plot.hsmm: no visible global function definition for ‘lines’
plot.hsmm: no visible global function definition for ‘legend’
plot.hsmm.data: no visible global function definition for ‘plot’
plot.hsmm.data: no visible global function definition for ‘ts’
plot.hsmm.data: no visible global function definition for ‘axTicks’
plot.hsmm.data: no visible global function definition for ‘abline’
predict.hmmspec: no visible global function definition for ‘predict’
predict.hsmmspec: no visible global function definition for ‘predict’
predict.smoothDiscrete: no visible global function definition for
  ‘predict’
print.smoothDiscrete: no visible global function definition for ‘str’
rnorm.hsmm: no visible global function definition for ‘rnorm’
rpois.hsmm: no visible global function definition for ‘rpois’
simulate.hsmmspec : fn: no visible global function definition for
  ‘rgamma’
smooth.discrete: no visible global function definition for ‘predict’
Undefined global functions or variables:
  abline approx axTicks cov.wt density dgamma dlnorm dnbinom dnorm
  dpois head legend lines optim plot predict rect rgamma rnbinom rnorm
  rpois str tail ts uniroot weighted.mean
Consider adding
  importFrom("graphics", "abline", "axTicks", "legend", "lines", "plot",
             "rect")
  importFrom("stats", "approx", "cov.wt", "density", "dgamma", "dlnorm",
             "dnbinom", "dnorm", "dpois", "optim", "predict", "rgamma",
             "rnbinom", "rnorm", "rpois", "ts", "uniroot",
             "weighted.mean")
  importFrom("utils", "head", "str", "tail")
to your NAMESPACE file.