liquidSVM (version 1.2.2)

getCover: Get Cover of partitioned SVM

Description

If you use voronoi=3 or voronoi=4 this retrieves the voronoi centers that have been found.

Usage

getCover(model, task = 1)

Arguments

model

the model

task

the task between 1 and number of tasks

Value

the indices of the samples in the training data set that were used as Voronoi partition centers.

Examples

# NOT RUN {
banana <- liquidData('banana-mc')
model <- mcSVM(Y~.,banana$train, voronoi=c(4,500),d=1)
# task 4 is predicting 2 vs 3
cover <- getCover(model,task=4)
centers <- cover$samples
# we are considering task 4 and hence only show labels 2 and 3:
bananaSub <- banana$train[banana$train$Y %in% c(2,3),]
plot(bananaSub[,-1],col=bananaSub$Y)
points(centers,pch='x',cex=2)

if(require(deldir)){
  voronoi <- deldir::deldir(centers$X1,centers$X2,rw=c(range(bananaSub$X1),range(bananaSub$X2)))
  plot(voronoi,wlines="tess",add=TRUE, lty=1)
  text(centers$X1,centers$X2,1:nrow(centers),pos=1)
}

# let us calculate for every sample in this task which cell it belongs to
distances <- as.matrix(dist(model$train_data))
cells <- apply(distances[model$train_labels %in% c(2,3),cover$indices],1,which.min)
# and you can check that the cell sizes are as reported in the training phase for task 4
table(cells)
# }