bic.glm.bg.data.frame : dropcols: no visible global function definition
  for ‘model.matrix’
bic.glm.bg.data.frame : dropcols: no visible global function definition
  for ‘terms.formula’
bic.glm.bg.data.frame : dropcols: no visible global function definition
  for ‘glm’
bic.glm.bg.data.frame : dropcols: no visible global function definition
  for ‘drop1’
bic.glm.bg.data.frame: no visible global function definition for
  ‘na.omit’
bic.glm.bg.data.frame: no visible global function definition for ‘glm’
bic.glm.bg.data.frame: no visible global function definition for
  ‘model.matrix’
bic.glm.bg.data.frame: no visible global function definition for
  ‘formula’
bic.glm.bg.formula: no visible global function definition for ‘terms’
bic.glm.bg.formula: no visible global function definition for
  ‘model.matrix’
bic.glm.bg.matrix : dropcols: no visible global function definition for
  ‘model.matrix’
bic.glm.bg.matrix : dropcols: no visible global function definition for
  ‘terms.formula’
bic.glm.bg.matrix : dropcols: no visible global function definition for
  ‘glm’
bic.glm.bg.matrix : dropcols: no visible global function definition for
  ‘drop1’
bic.glm.bg.matrix: no visible global function definition for ‘na.omit’
bic.glm.bg.matrix: no visible global function definition for ‘glm’
bic.glm.bg.matrix: no visible global function definition for
  ‘model.matrix’
bic.glm.bg.matrix: no visible global function definition for ‘formula’
do.estimate.mlogit: no visible global function definition for ‘maxLik’
do.mlogit2logit: no visible global function definition for ‘formula’
get.mnl.data: no visible global function definition for ‘abind’
imageplot.mlogit: no visible global function definition for
  ‘imageplot.bma’
mnl.spec: no visible global function definition for ‘formula’
mnl.spec: no visible global function definition for ‘terms’
summary.mnl: no visible global function definition for ‘coef’
summary.mnl: no visible global function definition for ‘pnorm’
Undefined global functions or variables:
  abind coef drop1 formula glm imageplot.bma maxLik model.matrix
  na.omit pnorm terms terms.formula
Consider adding
  importFrom("stats", "coef", "drop1", "formula", "glm", "model.matrix",
             "na.omit", "pnorm", "terms", "terms.formula")
to your NAMESPACE file.