ROCR (version 1.0-1)

performance-class: Class "performance"


Object to capture the result of a performance evaluation, optionally collecting evaluations from several cross-validation or bootstrapping runs.


Objects from the Class

Objects can be created by using the performance function.


A performance object can capture information from four different evaluation scenarios:
  • The behaviour of a cutoff-dependent performance measure across the range of all cutoffs (e.g.performance( predObj, 'acc' )). Here,x.valuescontains the cutoffs,y.valuesthe corresponding values of the performance measure, andalpha.valuesis empty.
  • The trade-off between two performance measures across the range of all cutoffs (e.g.performance( predObj, 'tpr', 'fpr' )). In this case, the cutoffs are stored inalpha.values, whilex.valuesandy.valuescontain the corresponding values of the two performance measures.
  • A performance measure that comes along with an obligatory second axis (e.g.performance( predObj, 'ecost' )). Here, the measure values are stored iny.values, while the corresponding values of the obligatory axis are stored inx.values, andalpha.valuesis empty.
  • A performance measure whose value is just a scalar (e.g.performance( predObj, 'auc' )). The value is then stored iny.values, whilex.valuesandalpha.valuesare empty.


A detailed list of references can be found on the ROCR homepage at

See Also

prediction, performance, prediction-class, plot.performance