Google Analytics scroll depth tracking report using the googleAnalyticsR & tidyr package. Check out this blog post tutorial on how to use this script: http://www.ryanpraski.com/scroll-depth-tracking-analysis-with-google-analytics-r/

pageScrollDepth.R

library(googleAnalyticsR)
library(tidyr)

#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 the Google Analytics Management API to see a list of Google Analytics accounts you have access to
my_accounts <- google_analytics_account_list()
View(my_accounts)

#Use my_accounts 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("2016-10-01", "2016-12-07"),
                         metrics = c("pageviews"),
                         dimensions = c("pagePath"),
                         anti_sample = TRUE)
#Event Query
df <- google_analytics_4(my_id, 
                               date_range = c("2016-10-01", "2016-12-07"),
                               metrics = c("totalEvents"),
                               dimensions = c("pagePath","eventLabel"),
                               filtersExpression = c("ga:eventLabel=~%|#disqus"),
                               anti_sample = TRUE)

#Use tidyr to make long data wide- move row data to columns
df2 <-spread(df,eventLabel,totalEvents,fill = 0)

#merge dataframees with pageview metric with scroll depth metrics
df3 <-merge(df1,df2)

#calculate percentage of people reaching each 25, 50, 75, 100, disqus comment on the page scroll depth
df3$percent25 <-round(df3$`25%`/df3$pageviews,digits = 2)
df3$percent50 <-round(df3$`50%`/df3$pageviews,digits = 2)
df3$percent75 <-round(df3$`75%`/df3$pageviews,digits = 2)
df3$percent_disqus <-round(df3$`#disqus_thread`/df3$pageviews,digits = 2)
df3$percent100 <-round(df3$`100%`/df3$pageviews,digits = 2)

#remove the raw counts from dateframe for page scroll depth and only show percent reaching each page depth
df4<-df3[,c("pagePath","pageviews","percent25","percent50","percent75","percent_disqus","percent100")]

#sort dataframe by pageviews
df5<-df4[order(-df4$pageviews),]