do.linear.conjoint: no visible global function definition for
  'as.formula'
do.linear.conjoint: no visible global function definition for 'lm'
do.linear.conjoint: no visible global function definition for
  'coefficients'
is.close.to.orthogonal: no visible global function definition for 'cor'
mc.add.to.design: no visible global function definition for 'combn'
mc.good.designs: no visible global function definition for 'combn'
Undefined global functions or variables:
  as.formula coefficients combn cor lm
Consider adding
  importFrom("stats", "as.formula", "coefficients", "cor", "lm")
  importFrom("utils", "combn")
to your NAMESPACE file.
do.linear.conjoint: no visible global function definition for
  ‘as.formula’
do.linear.conjoint: no visible global function definition for ‘lm’
do.linear.conjoint: no visible global function definition for
  ‘coefficients’
is.close.to.orthogonal: no visible global function definition for ‘cor’
mc.add.to.design: no visible global function definition for ‘combn’
mc.good.designs: no visible global function definition for ‘combn’
Undefined global functions or variables:
  as.formula coefficients combn cor lm
Consider adding
  importFrom("stats", "as.formula", "coefficients", "cor", "lm")
  importFrom("utils", "combn")
to your NAMESPACE file.
do.linear.conjoint: no visible global function definition for
  ‘as.formula’
do.linear.conjoint: no visible global function definition for ‘lm’
do.linear.conjoint: no visible global function definition for
  ‘coefficients’
is.close.to.orthogonal: no visible global function definition for ‘cor’
mc.add.to.design: no visible global function definition for ‘combn’
mc.good.designs: no visible global function definition for ‘combn’
Undefined global functions or variables:
  as.formula coefficients combn cor lm
Consider adding
  importFrom("stats", "as.formula", "coefficients", "cor", "lm")
  importFrom("utils", "combn")
to your NAMESPACE file.
do.linear.conjoint: no visible global function definition for
  ‘as.formula’
do.linear.conjoint: no visible global function definition for ‘lm’
do.linear.conjoint: no visible global function definition for
  ‘coefficients’
is.close.to.orthogonal: no visible global function definition for ‘cor’
mc.add.to.design: no visible global function definition for ‘combn’
mc.good.designs: no visible global function definition for ‘combn’
Undefined global functions or variables:
  as.formula coefficients combn cor lm
Consider adding
  importFrom("stats", "as.formula", "coefficients", "cor", "lm")
  importFrom("utils", "combn")
to your NAMESPACE file.
do.linear.conjoint: no visible global function definition for
  'as.formula'
do.linear.conjoint: no visible global function definition for 'lm'
do.linear.conjoint: no visible global function definition for
  'coefficients'
is.close.to.orthogonal: no visible global function definition for 'cor'
mc.add.to.design: no visible global function definition for 'combn'
mc.good.designs: no visible global function definition for 'combn'
Undefined global functions or variables:
  as.formula coefficients combn cor lm
Consider adding
  importFrom("stats", "as.formula", "coefficients", "cor", "lm")
  importFrom("utils", "combn")
to your NAMESPACE file.
do.linear.conjoint: no visible global function definition for
  ‘as.formula’
do.linear.conjoint: no visible global function definition for ‘lm’
do.linear.conjoint: no visible global function definition for
  ‘coefficients’
is.close.to.orthogonal: no visible global function definition for ‘cor’
mc.add.to.design: no visible global function definition for ‘combn’
mc.good.designs: no visible global function definition for ‘combn’
Undefined global functions or variables:
  as.formula coefficients combn cor lm
Consider adding
  importFrom("stats", "as.formula", "coefficients", "cor", "lm")
  importFrom("utils", "combn")
to your NAMESPACE file.
do.linear.conjoint: no visible global function definition for
  ‘as.formula’
do.linear.conjoint: no visible global function definition for ‘lm’
do.linear.conjoint: no visible global function definition for
  ‘coefficients’
is.close.to.orthogonal: no visible global function definition for ‘cor’
mc.add.to.design: no visible global function definition for ‘combn’
mc.good.designs: no visible global function definition for ‘combn’
Undefined global functions or variables:
  as.formula coefficients combn cor lm
Consider adding
  importFrom("stats", "as.formula", "coefficients", "cor", "lm")
  importFrom("utils", "combn")
to your NAMESPACE file.
do.linear.conjoint: no visible global function definition for
  ‘as.formula’
do.linear.conjoint: no visible global function definition for ‘lm’
do.linear.conjoint: no visible global function definition for
  ‘coefficients’
is.close.to.orthogonal: no visible global function definition for ‘cor’
mc.add.to.design: no visible global function definition for ‘combn’
mc.good.designs: no visible global function definition for ‘combn’
Undefined global functions or variables:
  as.formula coefficients combn cor lm
Consider adding
  importFrom("stats", "as.formula", "coefficients", "cor", "lm")
  importFrom("utils", "combn")
to your NAMESPACE file.
do.linear.conjoint: no visible global function definition for
  ‘as.formula’
do.linear.conjoint: no visible global function definition for ‘lm’
do.linear.conjoint: no visible global function definition for
  ‘coefficients’
is.close.to.orthogonal: no visible global function definition for ‘cor’
mc.add.to.design: no visible global function definition for ‘combn’
mc.good.designs: no visible global function definition for ‘combn’
Undefined global functions or variables:
  as.formula coefficients combn cor lm
Consider adding
  importFrom("stats", "as.formula", "coefficients", "cor", "lm")
  importFrom("utils", "combn")
to your NAMESPACE file.
do.linear.conjoint: no visible global function definition for
  'as.formula'
do.linear.conjoint: no visible global function definition for 'lm'
do.linear.conjoint: no visible global function definition for
  'coefficients'
is.close.to.orthogonal: no visible global function definition for 'cor'
mc.add.to.design: no visible global function definition for 'combn'
mc.good.designs: no visible global function definition for 'combn'
Undefined global functions or variables:
  as.formula coefficients combn cor lm
Consider adding
  importFrom("stats", "as.formula", "coefficients", "cor", "lm")
  importFrom("utils", "combn")
to your NAMESPACE file.
do.linear.conjoint: no visible global function definition for
  ‘as.formula’
do.linear.conjoint: no visible global function definition for ‘lm’
do.linear.conjoint: no visible global function definition for
  ‘coefficients’
is.close.to.orthogonal: no visible global function definition for ‘cor’
mc.add.to.design: no visible global function definition for ‘combn’
mc.good.designs: no visible global function definition for ‘combn’
Undefined global functions or variables:
  as.formula coefficients combn cor lm
Consider adding
  importFrom("stats", "as.formula", "coefficients", "cor", "lm")
  importFrom("utils", "combn")
to your NAMESPACE file.
do.linear.conjoint: no visible global function definition for
  ‘as.formula’
do.linear.conjoint: no visible global function definition for ‘lm’
do.linear.conjoint: no visible global function definition for
  ‘coefficients’
is.close.to.orthogonal: no visible global function definition for ‘cor’
mc.add.to.design: no visible global function definition for ‘combn’
mc.good.designs: no visible global function definition for ‘combn’
Undefined global functions or variables:
  as.formula coefficients combn cor lm
Consider adding
  importFrom("stats", "as.formula", "coefficients", "cor", "lm")
  importFrom("utils", "combn")
to your NAMESPACE file.
do.linear.conjoint: no visible global function definition for
  'as.formula'
do.linear.conjoint: no visible global function definition for 'lm'
do.linear.conjoint: no visible global function definition for
  'coefficients'
is.close.to.orthogonal: no visible global function definition for 'cor'
mc.add.to.design: no visible global function definition for 'combn'
mc.good.designs: no visible global function definition for 'combn'
Undefined global functions or variables:
  as.formula coefficients combn cor lm
Consider adding
  importFrom("stats", "as.formula", "coefficients", "cor", "lm")
  importFrom("utils", "combn")
to your NAMESPACE file.