Matrix factorisation demo using sparklyr

matrix-factorisation-demo.R

##############################
# 1. SETUP                   #
##############################

library(tidyverse)
library(sparklyr)
library(formattable)

set.seed(1234)

customGreen <- "#71CA97"
customRed <- "#ff7f7f"

user <- c(rep(1, 5), rep(2, 5), rep(3, 5), rep(4, 5), rep(5, 5), rep(6, 5))

item <- c(1, 3, 4, 5, 6,
          1, 2, 4, 5, 6,
          2, 3, 4, 5, 6,
          1, 2, 3, 4, 6,
          1, 2, 3, 4, 5,
          1, 2, 3, 5, 6)

rating <- c(5, 5, 1, 1, 1,
            5, 5, 1, 1, 1,
            5, 5, 1, 1, 1,
            1, 1, 1, 5, 5,
            1, 1, 1, 5, 5,
            1, 1, 1, 5, 5)

df <- data.frame(user, item, rating)

sc <- spark_connect(master = "local")
df_tbl <- copy_to(sc, df, overwrite = TRUE)

model <- ml_als(df_tbl, rating ~ user + item, rank = 2)

##############################
# 2. GRAPHICS                #
##############################

# 2.1. USER-ITEM MATRIX

df_table <- df %>% 
  mutate(item = str_replace_all(item, "1", "Airplane")) %>% 
  mutate(item = str_replace_all(item, "2", "Bridesmaids")) %>% 
  mutate(item = str_replace_all(item, "3", "Superbad")) %>% 
  mutate(item = str_replace_all(item, "4", "Halloween")) %>% 
  mutate(item = str_replace_all(item, "5", "Psycho")) %>% 
  mutate(item = str_replace_all(item, "6", "Scream")) %>% 
  mutate(user = str_replace_all(user, "1", "Amy")) %>% 
  mutate(user = str_replace_all(user, "2", "Ben")) %>% 
  mutate(user = str_replace_all(user, "3", "Chloe")) %>% 
  mutate(user = str_replace_all(user, "4", "Daniel")) %>% 
  mutate(user = str_replace_all(user, "5", "Emily")) %>% 
  mutate(user = str_replace_all(user, "6", "Fred")) %>% 
  mutate(item = factor(item, levels = c("Airplane", "Bridesmaids", "Superbad",
                                        "Halloween", "Psycho", "Scream"))) %>% 
  spread(item, rating)

colnames(df_table)[1] <- " "

formattable(df_table,
            list(" "  = formatter("span", style = ~ style(font.weight = "bold")),
                 `Airplane`= color_tile(customRed, customGreen),
                 `Bridesmaids`= color_tile(customRed, customGreen),
                 `Superbad`= color_tile(customRed, customGreen),
                 `Halloween`= color_tile(customRed, customGreen),
                 `Psycho`= color_tile(customRed, customGreen),
                 `Scream`= color_tile(customRed, customGreen))
)

# 2.2. ITEM MATRIX

item_matrix <- model$model$item_factors %>%
  as.data.frame() %>% 
  select(features_1, features_2) %>% 
  mutate(features_1 = round(as.numeric(features_1), 2)) %>% 
  mutate(features_2 = round(as.numeric(features_2), 2)) %>% 
  t() %>% 
  as.data.frame()

rownames(item_matrix) <- c("Latent Factor #1", "Latent Factor #2")
colnames(item_matrix) <- colnames(df_table[,2:ncol(df_table)])

item_matrix <- item_matrix %>% 
  tibble::rownames_to_column(var = " ")

formattable(item_matrix,
            list(" "  = formatter("span", style = ~ style(font.weight = "bold")),
                 `Airplane`= color_tile(customRed, customGreen),
                 `Bridesmaids`= color_tile(customRed, customGreen),
                 `Superbad`= color_tile(customRed, customGreen),
                 `Halloween`= color_tile(customRed, customGreen),
                 `Psycho`= color_tile(customRed, customGreen),
                 `Scream`= color_tile(customRed, customGreen))
)

# 2.3. USER MATRIX

user_matrix <- model$model$user_factors %>%
  as.data.frame() %>% 
  select(features_1, features_2) %>% 
  mutate(features_1 = round(as.numeric(features_1), 2)) %>% 
  mutate(features_2 = round(as.numeric(features_2), 2))

colnames(user_matrix) <- c("Latent Factor #1", "Latent Factor #2")
rownames(user_matrix) <- df_table$` `

user_matrix <- user_matrix %>% 
  tibble::rownames_to_column(var = " ")

formattable(user_matrix,
            list(" "  = formatter("span", style = ~ style(font.weight = "bold")),
                 `Latent Factor #1`= color_tile(customRed, customGreen),
                 `Latent Factor #2`= color_tile(customRed, customGreen))
)

# 2.4. ESTIMATED USER-ITEM MATRIX

item <- model$model$item_factors %>% 
  as.data.frame() %>% 
  select(features_1, features_2) %>% 
  t()

user <- model$model$user_factors %>% 
  as.data.frame() %>% 
  select(features_1, features_2) %>% 
  as.matrix()

estimated <- user %*% item %>%
  as.data.frame()  %>% 
  mutate(V1 = round(as.numeric(V1, 2))) %>% 
  mutate(V2 = round(as.numeric(V2, 2))) %>% 
  mutate(V3 = round(as.numeric(V3, 2))) %>% 
  mutate(V4 = round(as.numeric(V4, 2))) %>% 
  mutate(V5 = round(as.numeric(V5, 2))) %>% 
  mutate(V6 = round(as.numeric(V6, 2)))

rownames(estimated) <- df_table$` `
colnames(estimated) <- colnames(df_table[,2:ncol(df_table)])

estimated <- estimated %>% 
  tibble::rownames_to_column(var = " ")

formattable(estimated,
            list(" "  = formatter("span", style = ~ style(font.weight = "bold")),
                 `Airplane`= color_tile(customRed, customGreen),
                 `Bridesmaids`= color_tile(customRed, customGreen),
                 `Superbad`= color_tile(customRed, customGreen),
                 `Halloween`= color_tile(customRed, customGreen),
                 `Psycho`= color_tile(customRed, customGreen),
                 `Scream`= color_tile(customRed, customGreen))
)

##############################
# 3. DISCONNECT              #
##############################

spark_disconnect_all()