GHpoints: no visible global function definition for 'as.formula'
GHpoints: no visible global function definition for 'model.matrix'
GHpoints: no visible global function definition for 'dnorm'
GoF.gpcm : pearson.chi: no visible global function definition for
  'resid'
GoF.gpcm: no visible global function definition for 'pchisq'
GoF.rasch : rmvlogis: no visible global function definition for 'rnorm'
GoF.rasch : rmvlogis: no visible global function definition for
  'plogis'
GoF.rasch : rmvlogis: no visible global function definition for 'runif'
anova.gpcm: no visible global function definition for 'pchisq'
anova.gpcm: no visible global function definition for 'AIC'
anova.grm: no visible global function definition for 'pchisq'
anova.grm: no visible global function definition for 'AIC'
anova.ltm: no visible global function definition for 'pchisq'
anova.ltm: no visible global function definition for 'AIC'
anova.rasch: no visible global function definition for 'pchisq'
anova.rasch: no visible global function definition for 'AIC'
anova.tpm: no visible global function definition for 'pchisq'
anova.tpm: no visible global function definition for 'AIC'
biserial.cor: no visible global function definition for
  'complete.cases'
biserial.cor: no visible global function definition for 'sd'
chisq.irt: no visible global function definition for 'pchisq'
coef.ltm: no visible global function definition for 'plogis'
coef.rasch: no visible global function definition for 'plogis'
coef.tpm: no visible global function definition for 'plogis'
cprobs : <anonymous>: no visible global function definition for
  'plogis'
cronbach.alpha: no visible global function definition for 'var'
cronbach.alpha: no visible global function definition for
  'complete.cases'
cronbach.alpha: no visible binding for global variable 'sd'
cronbach.alpha: no visible global function definition for 'cor'
cronbach.alpha: no visible global function definition for 'quantile'
cumprobs : <anonymous>: no visible global function definition for
  'plogis'
descript: no visible global function definition for 'na.exclude'
descript: no visible global function definition for 'combn'
descript: no visible global function definition for 'chisq.test'
descript: no visible global function definition for 'qlogis'
factor.scores.ltm: no visible global function definition for
  'as.formula'
fitted.ltm: no visible global function definition for 'as.formula'
fitted.ltm: no visible global function definition for 'model.matrix'
fitted.tpm: no visible global function definition for 'plogis'
fscores.g : logf.z : <anonymous>: no visible global function definition
  for 'plogis'
fscores.g : logf.z: no visible global function definition for 'dnorm'
fscores.g : fscore: no visible global function definition for 'optim'
fscores.gp : logf.z: no visible global function definition for 'dnorm'
fscores.gp : fscore: no visible global function definition for 'optim'
fscores.l : logf.z: no visible global function definition for
  'model.matrix'
fscores.l : logf.z: no visible global function definition for 'dbinom'
fscores.l : logf.z: no visible global function definition for 'dnorm'
fscores.l : fscore: no visible global function definition for 'optim'
fscores.r : logf.z: no visible global function definition for 'dbinom'
fscores.r : logf.z: no visible global function definition for 'dnorm'
fscores.r : fscore: no visible global function definition for 'optim'
fscores.t : logf.z: no visible global function definition for 'plogis'
fscores.t : logf.z: no visible global function definition for 'dbinom'
fscores.t : logf.z: no visible global function definition for 'dnorm'
fscores.t : fscore: no visible global function definition for 'optim'
fscores.t: no visible global function definition for 'plogis'
gauher: no visible binding for global variable 'gh'
gpcm: no visible global function definition for 'optim'
gpcm: no visible global function definition for 'nlminb'
grm: no visible global function definition for 'optim'
infoGPCM: no visible binding for global variable 'tail'
information : f: no visible global function definition for 'plogis'
information: no visible global function definition for 'integrate'
iprobs : <anonymous>: no visible global function definition for
  'plogis'
item.fit: no visible binding for global variable 'median'
item.fit : itmFit: no visible global function definition for 'quantile'
item.fit : itmFit: no visible global function definition for
  'as.formula'
item.fit : itmFit: no visible global function definition for
  'model.matrix'
item.fit : itmFit: no visible global function definition for 'plogis'
item.fit: no visible global function definition for 'pchisq'
item.fit: no visible global function definition for 'plogis'
item.fit: no visible global function definition for 'update'
logLiktpm: no visible global function definition for 'plogis'
ltm: no visible global function definition for 'terms'
ltm.fit: no visible global function definition for 'optim'
margins.gpcm: no visible global function definition for
  'complete.cases'
margins.gpcm: no visible global function definition for 'combn'
margins.grm: no visible global function definition for 'complete.cases'
margins.grm: no visible global function definition for 'combn'
margins.ltm: no visible global function definition for 'plogis'
margins.ltm: no visible global function definition for 'combn'
margins.rasch: no visible global function definition for 'plogis'
margins.rasch: no visible global function definition for 'combn'
margins.tpm: no visible global function definition for 'plogis'
margins.tpm: no visible global function definition for 'combn'
person.fit : <anonymous>: no visible global function definition for
  'plogis'
person.fit : <anonymous>: no visible global function definition for
  'dbinom'
person.fit: no visible global function definition for 'plogis'
person.fit: no visible global function definition for 'pnorm'
person.fit: no visible global function definition for 'rnorm'
plot.aov.gpcm: no visible global function definition for 'qchisq'
plot.aov.gpcm: no visible global function definition for 'ppoints'
plot.aov.gpcm: no visible global function definition for 'plot'
plot.aov.gpcm: no visible global function definition for 'abline'
plot.descript: no visible global function definition for
  'complete.cases'
plot.descript: no visible global function definition for 'matplot'
plot.fscores: no visible global function definition for 'density'
plot.fscores: no visible global function definition for 'plot'
plot.fscores: no visible global function definition for 'stripchart'
plot.gpcm: no visible global function definition for 'palette'
plot.gpcm: no visible global function definition for 'par'
plot.gpcm: no visible global function definition for 'lines'
plot.gpcm: no visible global function definition for 'points'
plot.gpcm: no visible global function definition for 'text'
plot.grm: no visible global function definition for 'palette'
plot.grm: no visible global function definition for 'par'
plot.grm: no visible global function definition for 'lines'
plot.grm: no visible global function definition for 'points'
plot.grm: no visible global function definition for 'text'
plot.ltm: no visible global function definition for 'palette'
plot.ltm: no visible global function definition for 'par'
plot.ltm: no visible global function definition for 'plogis'
plot.ltm: no visible global function definition for 'lines'
plot.ltm: no visible global function definition for 'points'
plot.ltm: no visible global function definition for 'text'
plot.ltm: no visible global function definition for 'abline'
plot.ltm : f: no visible global function definition for 'plogis'
plot.ltm: no visible global function definition for 'persp'
plot.rasch: no visible global function definition for 'palette'
plot.rasch: no visible global function definition for 'par'
plot.rasch: no visible global function definition for 'plogis'
plot.rasch: no visible global function definition for 'lines'
plot.rasch: no visible global function definition for 'points'
plot.rasch: no visible global function definition for 'text'
plot.tpm: no visible global function definition for 'palette'
plot.tpm: no visible global function definition for 'par'
plot.tpm: no visible global function definition for 'plogis'
plot.tpm: no visible global function definition for 'lines'
plot.tpm: no visible global function definition for 'points'
plot.tpm: no visible global function definition for 'text'
plot.unidimTest: no visible global function definition for 'matplot'
print.margins.gpcm: no visible global function definition for 'combn'
print.margins.grm: no visible global function definition for 'combn'
print.tpm: no visible global function definition for 'plogis'
probs: no visible global function definition for 'plogis'
rasch: no visible global function definition for 'optim'
rcor.test: no visible global function definition for 'cor'
rcor.test: no visible global function definition for 'combn'
rcor.test: no visible global function definition for 'cor.test'
rmvlogis: no visible global function definition for 'rnorm'
rmvlogis: no visible global function definition for 'rlogis'
rmvlogis: no visible global function definition for 'rlnorm'
rmvlogis: no visible global function definition for 'runif'
rmvlogis: no visible global function definition for 'plogis'
rmvlogis: no visible global function definition for 'pnorm'
rmvlogis: no visible global function definition for 'rbinom'
rmvordlogis: no visible global function definition for 'rnorm'
rmvordlogis: no visible global function definition for 'rlogis'
rmvordlogis: no visible global function definition for 'rlnorm'
rmvordlogis: no visible global function definition for 'runif'
rmvordlogis : <anonymous>: no visible global function definition for
  'plogis'
scoretpm: no visible global function definition for 'plogis'
simulate.gpcm: no visible global function definition for 'runif'
simulate.grm: no visible global function definition for 'runif'
start.val.gpcm: no visible global function definition for 'rnorm'
start.val.gpcm: no visible global function definition for 'glm.fit'
start.val.gpcm: no visible global function definition for 'binomial'
start.val.gpcm: no visible global function definition for 'qlogis'
start.val.grm: no visible global function definition for 'rnorm'
start.val.grm: no visible global function definition for 'glm.fit'
start.val.grm: no visible global function definition for 'binomial'
start.val.grm: no visible global function definition for 'qlogis'
start.val.ltm: no visible global function definition for 'as.formula'
start.val.ltm: no visible global function definition for 'terms'
start.val.ltm: no visible global function definition for 'rnorm'
start.val.ltm: no visible global function definition for 'glm'
start.val.ltm: no visible global function definition for 'binomial'
start.val.rasch: no visible global function definition for 'rnorm'
start.val.rasch: no visible global function definition for 'glm.fit'
start.val.rasch: no visible global function definition for 'binomial'
start.val.tpm: no visible global function definition for 'rnorm'
start.val.tpm: no visible global function definition for 'glm.fit'
start.val.tpm: no visible global function definition for 'binomial'
start.val.tpm: no visible global function definition for 'qlogis'
summary.gpcm: no visible global function definition for 'AIC'
summary.tpm: no visible global function definition for 'plogis'
summary.tpm: no visible global function definition for 'AIC'
tpm: no visible global function definition for 'qlogis'
tpm: no visible global function definition for 'optim'
tpm: no visible global function definition for 'nlminb'
unidimTest: no visible global function definition for 'complete.cases'
unidimTest: no visible global function definition for 'plogis'
unidimTest: no visible global function definition for 'combn'
unidimTest: no visible global function definition for 'rnorm'
vcov.gpcm: no visible global function definition for 'ginv'
vcov.grm: no visible global function definition for 'ginv'
vcov.tpm : <anonymous>: no visible global function definition for
  'as.formula'
Undefined global functions or variables:
  AIC abline as.formula binomial chisq.test combn complete.cases cor
  cor.test dbinom density dnorm gh ginv glm glm.fit integrate lines
  matplot median model.matrix na.exclude nlminb optim palette par
  pchisq persp plogis plot pnorm points ppoints qchisq qlogis quantile
  rbinom resid rlnorm rlogis rnorm runif sd stripchart tail terms text
  update var
Consider adding
  importFrom("grDevices", "palette")
  importFrom("graphics", "abline", "lines", "matplot", "par", "persp",
             "plot", "points", "stripchart", "text")
  importFrom("stats", "AIC", "as.formula", "binomial", "chisq.test",
             "complete.cases", "cor", "cor.test", "dbinom", "density",
             "dnorm", "glm", "glm.fit", "integrate", "median",
             "model.matrix", "na.exclude", "nlminb", "optim", "pchisq",
             "plogis", "pnorm", "ppoints", "qchisq", "qlogis",
             "quantile", "rbinom", "resid", "rlnorm", "rlogis", "rnorm",
             "runif", "sd", "terms", "update", "var")
  importFrom("utils", "combn", "tail")
to your NAMESPACE file.