Run Kmeans in parallel to calculate WSS

kmeans_parallel.R

library(doParallel)
library(foreach)

my_data <- mtcars

# Within Sum of Squares
wss <- (nrow(my_data)-1)*sum(apply(my_data,2,var))

# Number of clusters
try_clusters <- seq(from = 2, to = 8, by = 1)

# Calculate the number of cores
no_cores <- detectCores() - 1

# Initiate cluster
cl <- makeCluster(no_cores)
registerDoParallel(cl)

# Calculating WSS for each cluster size in parallel
wss_results <- foreach::foreach (i = try_clusters) %dopar% {
  sum(kmeans(my_data, centers=i, iter.max = 1000)$withinss)
}

# Stop Clusters
stopCluster(cl)

# Plot WSS results
plot(try_clusters, unlist(wss_results), type="b", xlab="Number of Clusters",
     ylab="Within groups sum of squares")