R: Test DD-Classifier

ddalpha.getErrorRateCV {ddalpha} | R Documentation

## Test DD-Classifier

### Description

Performs a cross-validation procedure over the given data. On each step every `numchunks` observation is removed from the data, the DD-classifier is trained on these data and tested on the removed observations.

### Usage

    ddalpha.getErrorRateCV (data, numchunks = 10,  ...)

### Arguments

`data` | Matrix containing training sample where each of n rows is one object of the training sample where first d entries are inputs and the last entry is output (class label).
`numchunks` | number of subsets of testing data. Equals to the number of times the classifier is trained.
`...` | additional parameters passed to `ddalpha.train`

### Value

`errors` | the part of incorrectly classified data
`time` | the mean training time
`time_sd` | the standard deviation of training time

### See Also

`ddalpha.train` to train the DDα-classifier, `ddalpha.classify` for classification using DDα-classifier, `ddalpha.test` to test the DD-classifier on particular learning and testing data, `ddalpha.getErrorRatePart` to perform a benchmark study of the DD-classifier on particular data.

### Examples

    # Generate a bivariate normal location-shift classification task
    # containing 200 training objects and 200 to test with
    class1 <- mvrnorm(150, c(0,0),
                      matrix(c(1,1,1,4), nrow = 2, ncol = 2, byrow = TRUE))
    class2 <- mvrnorm(150, c(2,2),
                      matrix(c(1,1,1,4), nrow = 2, ncol = 2, byrow = TRUE))
    propertyVars <- c(1:2)
    classVar <- 3
    data <- rbind(cbind(class1, rep(1, 150)), cbind(class2, rep(2, 150)))

    # Train 1st DDalpha-classifier (default settings)
    # and get the classification error rate
    stat <- ddalpha.getErrorRateCV(data, numchunks = 5)
    cat("1. Classification error rate (defaults): ",
        stat$error, ".\n", sep = "")

    # Train 2nd DDalpha-classifier (zonoid depth, maximum Mahalanobis
    # depth classifier with defaults as outsider treatment)
    # and get the classification error rate
    stat2 <- ddalpha.getErrorRateCV(data, depth = "zonoid",
                              outsider.methods = "depth.Mahalanobis")
    cat("2. Classification error rate (depth.Mahalanobis): ",
        stat2$error, ".\n", sep = "")

[Package ddalpha version 1.3.4 Index]