performance-class: Class "performance"
Description
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.Details
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.
References
A detailed list of references can be found on the ROCR
homepage at http://rocr.bioinf.mpi-sb.mpg.de.