.EstimateSplineConstrainedC: no visible global function definition for
  ‘as.formula’
.EstimateSplineConstrainedC: no visible global function definition for
  ‘vcov’
.EstimateSplineConstrainedCC: no visible global function definition for
  ‘as.formula’
.EstimateSplineConstrainedCC: no visible global function definition for
  ‘glm’
.EstimateSplineConstrainedCC: no visible binding for global variable
  ‘binomial’
.EstimateSplineConstrainedCC: no visible global function definition for
  ‘vcov’
.EstimateSplineConstrainedCC: no visible global function definition for
  ‘logLik’
.EstimateSplineConstrainedNCC: no visible global function definition
  for ‘as.formula’
.EstimateSplineConstrainedNCC: no visible global function definition
  for ‘vcov’
.EstimateSplineUnconstrainedC: no visible global function definition
  for ‘as.formula’
.EstimateSplineUnconstrainedC: no visible global function definition
  for ‘vcov’
.EstimateSplineUnconstrainedCC: no visible global function definition
  for ‘as.formula’
.EstimateSplineUnconstrainedCC: no visible global function definition
  for ‘glm’
.EstimateSplineUnconstrainedCC: no visible binding for global variable
  ‘binomial’
.EstimateSplineUnconstrainedCC: no visible global function definition
  for ‘vcov’
.EstimateSplineUnconstrainedCC: no visible global function definition
  for ‘logLik’
.EstimateSplineUnconstrainedNCC: no visible global function definition
  for ‘as.formula’
.EstimateSplineUnconstrainedNCC: no visible global function definition
  for ‘vcov’
.knots.equi: no visible global function definition for ‘quantile’
.sumWCEall: no visible global function definition for ‘pnorm’
.sumWCEbest: no visible global function definition for ‘pnorm’
checkWCE: no visible global function definition for ‘na.omit’
plot.WCE: no visible global function definition for ‘matplot’
plot.WCE: no visible global function definition for ‘title’
plot.WCE: no visible global function definition for ‘points’
plot.WCE: no visible global function definition for ‘legend’
plot.WCE: no visible global function definition for ‘plot’
plot.WCE: no visible global function definition for ‘lines’
Undefined global functions or variables:
  as.formula binomial glm legend lines logLik matplot na.omit plot
  pnorm points quantile title vcov
Consider adding
  importFrom("graphics", "legend", "lines", "matplot", "plot", "points",
             "title")
  importFrom("stats", "as.formula", "binomial", "glm", "logLik",
             "na.omit", "pnorm", "quantile", "vcov")
to your NAMESPACE file.