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.
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 standart 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 = "")