NN {dbscan} | R Documentation |
Helper functions for nearest neighbors (kNN and frNN).
adjacencylist(x, ...) ## S3 method for class 'NN' plot(x, data, main = NULL, ...)
x |
a nearest neighbor object (of class kNN or frNN). |
... |
further arguments are currently ignored. |
data |
data with the coordinates for plotting. |
main |
main title for the plot. |
adjacencylist
returns
a list with one element for each original data point. Each element contains
the row ids of the nearest neighbors. The adjacency list can be used to create
for example a graph object.
Michael Hahsler
data(iris) x <- iris[, -5] # finding kNN directly in data (using a kd-tree) nn <- kNN(x, k=5) nn # plot the kNN where NN are shown as line conecting points. plot(nn, x) # show the first few elements of the adjacency list head(adjacencylist(nn)) # create a graph and find connected components (if igraph is installed) if("igraph" %in% installed.packages()){ library("igraph") g <- graph_from_adj_list(adjacencylist(nn)) comp <- components(g) plot(x, col = comp$membership) # detect clusters (communities) with the label propagation algorithm cl <- membership(cluster_label_prop(g)) plot(x, col = cl) }