Found an obsolete/platform-specific call in the following function:
  ‘zipfR.begin.plot’
Found the platform-specific devices:
  ‘X11’ ‘quartz’
dev.new() is the preferred way to open a new device, in the unlikely
event one is needed.
EVm.spc: no visible global function definition for ‘dbinom’
Rbeta: no visible global function definition for ‘pbeta’
Rbeta.inv: no visible global function definition for ‘qbeta’
Rgamma: no visible global function definition for ‘pgamma’
Rgamma.inv: no visible global function definition for ‘qgamma’
confint.lnre : <anonymous>: no visible global function definition for
  ‘sd’
confint.lnre : <anonymous>: no visible global function definition for
  ‘qnorm’
confint.lnre : <anonymous>: no visible global function definition for
  ‘median’
confint.lnre: no visible global function definition for ‘hist’
confint.lnre: no visible global function definition for ‘abline’
confint.lnre: no visible global function definition for ‘lines’
confint.lnre: no visible global function definition for ‘density’
estimate.model.lnre: no visible global function definition for ‘nlm’
estimate.model.lnre: no visible global function definition for ‘optim’
estimate.model.lnre.fzm : compute.B: no visible global function
  definition for ‘uniroot’
estimate.model.lnre.fzm: no visible global function definition for
  ‘optim’
estimate.model.lnre.fzm: no visible global function definition for
  ‘nlm’
estimate.model.lnre.zm : compute.B: no visible global function
  definition for ‘uniroot’
estimate.model.lnre.zm: no visible global function definition for ‘nlm’
lnre.bootstrap: no visible global function definition for
  ‘txtProgressBar’
lnre.bootstrap: no visible global function definition for ‘is’
lnre.bootstrap: no visible global function definition for
  ‘setTxtProgressBar’
lnre.goodness.of.fit: no visible global function definition for
  ‘pchisq’
plot.spc: no visible global function definition for ‘barplot’
plot.spc: no visible global function definition for ‘plot’
plot.spc: no visible global function definition for ‘qnorm’
plot.spc: no visible global function definition for ‘segments’
plot.spc: no visible global function definition for ‘lines’
plot.tfl : <anonymous>: no visible global function definition for
  ‘na.omit’
plot.tfl: no visible global function definition for ‘plot’
plot.tfl: no visible global function definition for ‘points’
plot.vgc: no visible global function definition for ‘plot’
plot.vgc: no visible global function definition for ‘qnorm’
plot.vgc: no visible global function definition for ‘segments’
plot.vgc: no visible global function definition for ‘lines’
plot.vgc: no visible global function definition for ‘abline’
read.spc: no visible global function definition for ‘read.delim’
read.tfl: no visible global function definition for ‘read.delim’
read.vgc: no visible global function definition for ‘read.delim’
rlnre.lnre: no visible global function definition for ‘runif’
summary.tfl: no visible global function definition for ‘median’
write.spc: no visible global function definition for ‘write.table’
write.tfl: no visible global function definition for ‘write.table’
write.vgc: no visible global function definition for ‘write.table’
zipfR.begin.plot: no visible global function definition for ‘dev.off’
zipfR.begin.plot: no visible global function definition for ‘X11’
zipfR.begin.plot: no visible global function definition for ‘quartz’
zipfR.begin.plot: no visible global function definition for ‘par’
zipfR.begin.plot: no visible global function definition for ‘png’
zipfR.begin.plot: no visible global function definition for
  ‘postscript’
zipfR.begin.plot: no visible global function definition for ‘pdf’
zipfR.begin.plot: no visible global function definition for ‘dev.cur’
zipfR.begin.plot: no visible binding for global variable ‘par’
zipfR.end.plot: no visible global function definition for ‘dev.off’
zipfR.tflsplit: no visible global function definition for ‘rhyper’
Undefined global functions or variables:
  X11 abline barplot dbinom density dev.cur dev.off hist is lines
  median na.omit nlm optim par pbeta pchisq pdf pgamma plot png points
  postscript qbeta qgamma qnorm quartz read.delim rhyper runif sd
  segments setTxtProgressBar txtProgressBar uniroot write.table
Consider adding
  importFrom("grDevices", "X11", "dev.cur", "dev.off", "pdf", "png",
             "postscript", "quartz")
  importFrom("graphics", "abline", "barplot", "hist", "lines", "par",
             "plot", "points", "segments")
  importFrom("methods", "is")
  importFrom("stats", "dbinom", "density", "median", "na.omit", "nlm",
             "optim", "pbeta", "pchisq", "pgamma", "qbeta", "qgamma",
             "qnorm", "rhyper", "runif", "sd", "uniroot")
  importFrom("utils", "read.delim", "setTxtProgressBar",
             "txtProgressBar", "write.table")
to your NAMESPACE file (and ensure that your DESCRIPTION Imports field
contains 'methods').