In schliebs/voteR: Variety of Open Tools for Electoral Research

knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)

introductory remarks

library(voteR)

Scrape all available polls.

df <- scrape_wahlrecht_bund()

Explore how many polls are available in total:

nrow(df)

And split up by institute:

df %>% pull(institute) %>% table()

Check out the availbe variables:

colnames(df)

Print the first 10 observations to see an example:

df %>% slice(1:10)

Select polling institutes

Furthermore, a set of institutes to be included can be selected via a character vector passed to the institutes parameter. Possible options include allensbach, emnid, forsa, politbarometer, gms, dimap, insa, and yougov

scrape_wahlrecht_bund(institutes = c("dimap","politbarometer"))

Include Unweighted Raw Data (if available)

Lastly, for some institutes (namely Politbarometer and GMS), it is also possible to include (declared) raw-data which has not been post-treated or weighted. These data points are excluded by default but can be included by using the include_rawdata = TRUE option.

scrape_wahlrecht_bund(include_rawdata = T) %>% 
  filter(raw_by_institute == T)

Visualize Polls

library(ggplot2)

ggpoll <- 
  df %>% 
  gather(party,pollscore,`cdu/csu`:others) %>% 
  filter(!party %in% c("others")) %>%
  ggplot(aes(x = as.Date(date,"%d.%m.%Y"),
                 y = pollscore)) + 
  geom_point(alpha = 0.1) + 
  geom_smooth(aes(col = party)) + 
  facet_wrap(~party,scales = "free")
ggpoll

Restrict graph to last legislative period only:

ggpoll2 <- 
  ggpoll + 
  scale_x_date(limits = c(as.Date("2017-09-22"),Sys.Date()))
ggpoll2

And adjust party colors accordingly:

partycolors_ger <- c(spd = "red",
                     cdu = "black",
                     cdu_csu = "black",
                     `cdu/csu` = "black",
                     csu = "darkblue",
                     gruene = "darkgreen",
                     grüne = "darkgreen",
                     fdp =  "#999900",
                     afd = "blue",
                     piraten = "orange",
                     linke = "purple",
                     andere = "black",
                     sonstige = "grey")

ggpoll2 + 
  scale_color_manual(values = partycolors_ger) + 
  theme_minimal() + 
  labs(x = "Date",
       y = "Pollscore")