R Script to create a heatmap the visualizes Google Analytics page scroll depth tracking. Tutorial here: http://www.ryanpraski.com/r-heatmap-tutorial-for-google-analytics/

heatmap_page_scroll_depth_Google_Analytics_R.R

library(googleAnalyticsR)
library(ggplot2)

#Authorized Google Analytics R- this will open a webpage
#You must be logged into your Google Analytics account on your web browser
ga_auth()

#Use google_analytics_account_list() to find the viewId. Make sure to replace this with your viewId.
my_id <- 94579701

#Page View Query
df1 <- google_analytics_4(my_id, 
                          date_range = c("365daysAgo", "yesterday"),
                          metrics = c("pageviews"),
                          dimensions = c("pagePath"),
                          anti_sample = TRUE)

#Event Query this assumes that you are tracking % page scroll and #disqus_thread.
#Change the filtersExpression eventLable to match your scroll depth data
df <- google_analytics_4(my_id, 
                         date_range = c("365daysAgo", "yesterday"),
                         metrics = c("totalEvents"),
                         dimensions = c("pagePath","eventLabel"),
                         filtersExpression = c("ga:eventLabel=~%|#disqus"),
                         anti_sample = TRUE)

#Merge the page and scroll depth data into a single data frame
#Order page by top 15 pageviews and only include top 15 combined dataframe
df2<-merge(head(df1[order(-df1$pageviews),],n=15),df)

#Add a new column to that shows the percent of pageviews reaching each scroll depth for each page
df2$percent <-round(df2$totalEvents/df2$pageviews,digits = 2)

#Order pagePath by pageviews for heatmap 
#And convert pagePath to a factor variable so the ggplot heatmap follows the sort order
df2$pagePath <- factor(df2$pagePath, levels = df2$pagePath[order(df2$pageview)])

#Heatmap ggplot
df2 %>%
  ggplot(aes(x=eventLabel, y=pagePath, fill=percent)) + 
  geom_tile() + 
  scale_fill_continuous(low = 'white', high = 'red') +
  scale_x_discrete(limits=c('25%','50%','75%', '#disqus_thread', '100%')) +
  scale_y_discrete()+
  theme_bw() + 
  theme(panel.grid.major = element_blank())