sonicpi-googlegroups

library(rvest)
library(magrittr)
library(dplyr)
library(purrr)
library(lubridate)
library(tidyr)
library(ggplot2)
library(scales)

setwd("...working directory...")

#html page of the sonicpi google group
html <- read_html("sonicpi.html")

table <- html %>%
          html_nodes(".IVILX2C-p-V") %>%
          html_table() %>%
          `[[`(1)

f <- safely(mdy)
d1 <- f(table$X3)[[1]] 

d1[is.na(d1)] <- mdy(paste(table$X3[is.na(d1)], 2016))
d1[is.na(d1)] <- today()

table$date <- d1

table$posts <- extract_numeric(table$X2)

table_monthly <- table %>% 
                  group_by(month=as.Date(cut(.$date, breaks="month"))) %>%
                  summarise(posts = sum(posts))

ggplot(data=table_monthly, aes(x=month, y=posts)) + 
  geom_bar(stat="identity", fill="deeppink1") +
  scale_x_date(date_labels="%Y-%m", date_breaks="1 month", limits=c(as.Date("2013-09-01"), as.Date("2016-06-01"))) + 
  labs(y="# posts per month", title="# of posts on sonic-pi google groups") + 
  geom_smooth(se=FALSE, linetype=5, col="gray65") + 
  theme(axis.text.x = element_text(angle=90, vjust=0.5))