Ergasia007

colnames(Pizza_Sale) = c("pizza_id","order_id","pizza_name_id","quantity","order_date","order_time","unit_price","total_price","pizza_size","pizza_category","pizza_ingredients","pizza_name")

Pizza_Sale$pizza_id = NULL
Pizza_Sale$order_id = NULL
Pizza_Sale$pizza_name_id = NULL
Pizza_Sale$order_date = NULL
Pizza_Sale$order_time = NULL
Pizza_Sale$pizza_ingredients = NULL
Pizza_Sale$pizza_name = NULL

distances = dist(Pizza_Sale[2:5], method = "euclidean")

## Warning in dist(Pizza_Sale[2:5], method = "euclidean"): NAs introduced by
## coercion

clusterPizzas = hclust(distances, method = "ward.D2")
clusterGroups = cutree(clusterPizzas, k = 5)
plot(clusterPizzas)