.combine.performance.objects: no visible global function definition for
  ‘approxfun’
.get.arglist: no visible binding for global variable ‘plot.default’
.get.arglist: no visible global function definition for ‘par’
.get.arglist: no visible binding for global variable ‘plot.xy’
.intersection.point: no visible global function definition for
  ‘uniroot’
.performance.auc: no visible global function definition for ‘approxfun’
.performance.calibration.error: no visible global function definition
  for ‘median’
.performance.chisq: no visible global function definition for
  ‘chisq.test’
.performance.plot.canvas: no visible global function definition for
  ‘axTicks’
.performance.plot.canvas: no visible global function definition for
  ‘approxfun’
.performance.plot.canvas: no visible global function definition for
  ‘rect’
.performance.plot.horizontal.avg: no visible global function definition
  for ‘approxfun’
.performance.plot.horizontal.avg : <anonymous>: no visible global
  function definition for ‘approxfun’
.performance.plot.horizontal.avg: no visible binding for global
  variable ‘sd’
.performance.plot.no.avg: no visible global function definition for
  ‘xy.coords’
.performance.plot.no.avg: no visible global function definition for
  ‘approxfun’
.performance.plot.threshold.avg: no visible global function definition
  for ‘approxfun’
.performance.plot.threshold.avg : <anonymous>: no visible global
  function definition for ‘approxfun’
.performance.plot.threshold.avg: no visible binding for global variable
  ‘sd’
.performance.plot.vertical.avg: no visible global function definition
  for ‘approxfun’
.performance.plot.vertical.avg : <anonymous>: no visible global
  function definition for ‘approxfun’
.performance.plot.vertical.avg: no visible binding for global variable
  ‘sd’
.performance.precision.recall.break.even.point: no visible global
  function definition for ‘uniroot’
.performance.precision.recall.break.even.point: no visible global
  function definition for ‘approxfun’
.performance.rocconvexhull: no visible global function definition for
  ‘chull’
.plot.performance: no visible global function definition for ‘rainbow’
plot,performance-missing: no visible global function definition for
  ‘rainbow’
Undefined global functions or variables:
  approxfun axTicks chisq.test chull median par plot.default plot.xy
  rainbow rect sd uniroot xy.coords
Consider adding
  importFrom("grDevices", "chull", "rainbow", "xy.coords")
  importFrom("graphics", "axTicks", "par", "plot.default", "plot.xy",
             "rect")
  importFrom("stats", "approxfun", "chisq.test", "median", "sd",
             "uniroot")
to your NAMESPACE file.