lbfit.nonpar : fitnonpar: no visible global function definition for
  ‘stepfun’
lbfit.nonpar : bootnonpar: no visible binding for global variable
  ‘quantile’
lbfit.nonpar : bootnonpar: no visible binding for global variable ‘sd’
lbfit.nonpar : bootnonpar: no visible global function definition for
  ‘qnorm’
lbfit.nonpar : bootnonpar: no visible binding for global variable
  ‘median’
lbfit.nonpar : bootnonpar: no visible global function definition for
  ‘stepfun’
lbfit.par : weibull.fit.optim : loglik.lb.weibull: no visible global
  function definition for ‘dweibull’
lbfit.par : weibull.fit.optim : loglik.lb.weibull: no visible global
  function definition for ‘pweibull’
lbfit.par : weibull.fit.optim: no visible global function definition
  for ‘optim’
lbfit.par : gamma.fit.optim : loglik.lb.gamma: no visible global
  function definition for ‘dgamma’
lbfit.par : gamma.fit.optim : loglik.lb.gamma: no visible global
  function definition for ‘pgamma’
lbfit.par : gamma.fit.optim: no visible global function definition for
  ‘optim’
lbfit.par : exponential.fit.optim : loglik.lb.exp: no visible global
  function definition for ‘dweibull’
lbfit.par : exponential.fit.optim : loglik.lb.exp: no visible global
  function definition for ‘pweibull’
lbfit.par : exponential.fit.optim: no visible global function
  definition for ‘optim’
lbfit.par : lognormal.fit.optim : loglik.lb.lognorm: no visible global
  function definition for ‘dlnorm’
lbfit.par : lognormal.fit.optim : loglik.lb.lognorm: no visible global
  function definition for ‘plnorm’
lbfit.par : lognormal.fit.optim: no visible global function definition
  for ‘optim’
lbfit.par : loglogistic.fit.optim : loglik.lb.loglogis: no visible
  global function definition for ‘pllogis’
lbfit.par : loglogistic.fit.optim: no visible global function
  definition for ‘optim’
lbsample: no visible global function definition for ‘rexp’
lbsample : lbsample.weibull: no visible global function definition for
  ‘rgamma’
lbsample : lbsample.weibull: no visible global function definition for
  ‘runif’
lbsample : lbsample.gamma: no visible global function definition for
  ‘rgamma’
lbsample : lbsample.gamma: no visible global function definition for
  ‘runif’
lbsample : lbsample.lognormal: no visible global function definition
  for ‘rnorm’
lbsample : lbsample.lognormal: no visible global function definition
  for ‘runif’
lbsample : lbsample.loglogistic: no visible global function definition
  for ‘rbeta’
lbsample : lbsample.loglogistic: no visible global function definition
  for ‘runif’
Undefined global functions or variables:
  dgamma dlnorm dweibull median optim pgamma pllogis plnorm pweibull
  qnorm quantile rbeta rexp rgamma rnorm runif sd stepfun
Consider adding
  importFrom("stats", "dgamma", "dlnorm", "dweibull", "median", "optim",
             "pgamma", "plnorm", "pweibull", "qnorm", "quantile",
             "rbeta", "rexp", "rgamma", "rnorm", "runif", "sd",
             "stepfun")
to your NAMESPACE file.