getIterationsPreds {performanceEstimation}

Obtaining the predictions returned by a workflow when applied to a task, on a particular iteration of the estimation process, or on all iterations

Description

In the estimation process workflows are applied many times to different train+test samples of each task. We call these repetitions, the iterations of the estimation process. On each of these executions of the workflows they must return the predictions for the test set. This function allows you to obtain these predictions. The function also allows you to obtain the predictions on all iterations, instead of a single iteration.

Usage

getIterationsPreds(obj, workflow = 1, task = 1, rep, fold, it, predComp="preds")

Arguments

obj

A ComparisonResults object

workflow

A string with the ID of a workflow (it can also be an integer). It defaults to 1 (the first workflow of the estimation experiment)

task

A string with the ID of a task (it can also be an integer). It defaults to 1 (the first task of the estimation experiment)

rep

An integer representing the repetition, which allows you to identify the iteration you want to inspect. You need to specify either this argument together with the argument fold, or only the argument it

fold

An integer representing the fold, which allows you to identify the iteration you want to inspect. You need to specify either this argument together with the argument rep, or only the argument it

it

An integer representing the iteration you want to inspect. Alternatively, for cross validation experiments, you may instead specify the repetition id and the fold id (arguments rep and fold, respectivily)

predComp

A string with the name of the component of the list returned by the workflow that contains the predictions (it defaults to "preds")

Value

The result is either a vector of the predictions of a particular iteration or a matrix with the predictions on all iterations

Author(s)

Luis Torgo [e-mail]

References

Torgo, L. (2014) An Infra-Structure for Performance Estimation and Experimental Comparison of Predictive Models in R. arXiv:1412.0436 [cs.MS] http://arxiv.org/abs/1412.0436

See Also

getScores, getIterationsInfo, performanceEstimation

Examples

## Not run: 
## Estimating MSE for 3 variants of both
## regression trees and SVMs, on  two data sets, using one repetition
## of 10-fold CV
library(e1071)
data(swiss)

## running the estimation experiment
res <- performanceEstimation(
  PredTask(Infant.Mortality ~ .,swiss),
  workflowVariants(learner="svm",
                   learner.pars=list(cost=c(1,10),gamma=c(0.01,0.5))),
  EstimationTask("mse",method=CV(nReps=2,nFolds=5))
  )

## Get the iterations scores of svm.v2 on swiss
getIterationsPreds(res,"svm.v2","swiss.Infant.Mortality",rep=1,fold=2)
## this would get the same
getIterationsPreds(res,"svm.v2","swiss.Infant.Mortality",it=2)

getIterationsPreds(res,"svm.v2","swiss.Infant.Mortality",rep=2,fold=3)
## this would get the same
getIterationsPreds(res,"svm.v2","swiss.Infant.Mortality",it=8)

## Get the results of all iterations
getIterationsPreds(res,"svm.v1","swiss.Infant.Mortality")


## End(Not run)