PEMM_fun : find.lambda: no visible global function definition for
  'optimize'
PEMM_fun: no visible global function definition for 'cov'
Undefined global functions or variables:
  cov optimize
Consider adding
  importFrom("stats", "cov", "optimize")
to your NAMESPACE file.
PEMM_fun : find.lambda: no visible global function definition for
  ‘optimize’
PEMM_fun: no visible global function definition for ‘cov’
Undefined global functions or variables:
  cov optimize
Consider adding
  importFrom("stats", "cov", "optimize")
to your NAMESPACE file.
PEMM_fun : find.lambda: no visible global function definition for
  ‘optimize’
PEMM_fun: no visible global function definition for ‘cov’
Undefined global functions or variables:
  cov optimize
Consider adding
  importFrom("stats", "cov", "optimize")
to your NAMESPACE file.
PEMM_fun : find.lambda: no visible global function definition for
  'optimize'
PEMM_fun: no visible global function definition for 'cov'
Undefined global functions or variables:
  cov optimize
Consider adding
  importFrom("stats", "cov", "optimize")
to your NAMESPACE file.
PEMM_fun : find.lambda: no visible global function definition for
  ‘optimize’
PEMM_fun: no visible global function definition for ‘cov’
Undefined global functions or variables:
  cov optimize
Consider adding
  importFrom("stats", "cov", "optimize")
to your NAMESPACE file.
PEMM_fun : find.lambda: no visible global function definition for
  ‘optimize’
PEMM_fun: no visible global function definition for ‘cov’
Undefined global functions or variables:
  cov optimize
Consider adding
  importFrom("stats", "cov", "optimize")
to your NAMESPACE file.
PEMM_fun : find.lambda: no visible global function definition for
  ‘optimize’
PEMM_fun: no visible global function definition for ‘cov’
Undefined global functions or variables:
  cov optimize
Consider adding
  importFrom("stats", "cov", "optimize")
to your NAMESPACE file.
PEMM_fun : find.lambda: no visible global function definition for
  ‘optimize’
PEMM_fun: no visible global function definition for ‘cov’
Undefined global functions or variables:
  cov optimize
Consider adding
  importFrom("stats", "cov", "optimize")
to your NAMESPACE file.
PEMM_fun : find.lambda: no visible global function definition for
  'optimize'
PEMM_fun: no visible global function definition for 'cov'
Undefined global functions or variables:
  cov optimize
Consider adding
  importFrom("stats", "cov", "optimize")
to your NAMESPACE file.
PEMM_fun : find.lambda: no visible global function definition for
  ‘optimize’
PEMM_fun: no visible global function definition for ‘cov’
Undefined global functions or variables:
  cov optimize
Consider adding
  importFrom("stats", "cov", "optimize")
to your NAMESPACE file.
PEMM_fun : find.lambda: no visible global function definition for
  ‘optimize’
PEMM_fun: no visible global function definition for ‘cov’
Undefined global functions or variables:
  cov optimize
Consider adding
  importFrom("stats", "cov", "optimize")
to your NAMESPACE file.
PEMM_fun : find.lambda: no visible global function definition for
  'optimize'
PEMM_fun: no visible global function definition for 'cov'
Undefined global functions or variables:
  cov optimize
Consider adding
  importFrom("stats", "cov", "optimize")
to your NAMESPACE file.