R: Class "prediction"

prediction-class {ROCR} | R Documentation

## Class "prediction"

### Description

Object to encapsulate numerical predictions together with the corresponding true class labels, optionally collecting predictions and labels for several cross-validation or bootstrapping runs.

### Objects from the Class

Objects can be created by using the `prediction` function.

### Slots

`predictions`:

  A list, in which each element is a vector of predictions (the list has length > 1 for x-validation data.)

`labels`:

  Analogously, a list in which each element is a vector of true class labels.

`cutoffs`:

  A list in which each element is a vector of all necessary cutoffs. Each cutoff vector consists of the predicted scores (duplicates removed), in descending order.

`fp`:

  A list in which each element is a vector of the number (not the rate!) of false positives induced by the cutoffs given in the corresponding 'cutoffs' list entry.

`tp`:

  As fp, but for true positives.

`tn`:

  As fp, but for true negatives.

`fn`:

  As fp, but for false negatives.

`n.pos`:

  A list in which each element contains the number of positive samples in the given x-validation run.

`n.neg`:

  As n.pos, but for negative samples.

`n.pos.pred`:

  A list in which each element is a vector of the number of samples predicted as positive at the cutoffs given in the corresponding 'cutoffs' entry.

`n.neg.pred`:

  As n.pos.pred, but for negatively predicted samples.

### Note

Every `prediction` object contains information about the 2x2 contingency table consisting of tp,tn,fp, and fn, along with the marginal sums n.pos,n.neg,n.pos.pred,n.neg.pred, because these form the basis for many derived performance measures.

### Author(s)

Tobias Sing tobias.sing@mpi-sb.mpg.de, Oliver Sander osander@mpi-sb.mpg.de

### References

A detailed list of references can be found on the ROCR homepage at http://rocr.bioinf.mpi-sb.mpg.de.

### See Also

`prediction`, `performance`, `performance-class`, `plot.performance`

[Package ROCR version 1.0-7 Index]