Sys.setlocale("LC_TIME", "English")
library(ggplot2)
library(anytime)
library(tidyverse)
library(svglite)
library(Rcpp)

polls <- read.table("DE.csv", header=T, sep=",", fileEncoding="UTF-8", stringsAsFactor=F)
polls$polldate <- as.Date(anydate(polls$polldate))

spansize <- 0.1           # general smoothing parameter for trend line
nnum <- 600                 # number of points used for trendline (resolution)
startdate <- '2021-09-19'   # date of previous election
enddate <- '2026-09-20'     # (latest) date of next election

# retrieve party names from CSV
party1 <- colnames(polls)[2]
party2 <- colnames(polls)[3]
party3 <- colnames(polls)[4]
party4 <- colnames(polls)[5]
party5 <- colnames(polls)[6]

# define party colors (taken from https://wiki.riteme.site/wiki/Category:Germany_political_party_colour_templates)
col1 <- '#2E4EA4'
col2 <- '#CC1111'
col3 <- '#4488CC'
col4 <- '#FFC003'
col5 <- '#0AD1C9'

transp <-'55'       # transparency level of points

graph <- ggplot(polls)+
  geom_vline(xintercept = as.Date(startdate), color='#aaaaaabb')+       # vertical line (last election)
  geom_vline(xintercept = as.Date(enddate), color='#aaaaaabb')+         # vertical line (next election)
  geom_segment(aes(x=as.Date(startdate), xend=as.Date(enddate), y=5, yend=5), color='#666666bb', linetype='dashed')+      # horizontal line (election threshold 5%)
  # add poll points
  geom_point(aes_string(x='polldate',y=party1),size=ifelse(polls$polldate==startdate | polls$polldate==enddate,3,1.5),shape=ifelse(polls$polldate==startdate | polls$polldate==enddate,23,21),color=paste0(col1,transp),fill=paste0(col1,transp))+
  geom_point(aes_string(x='polldate',y=party2),size=ifelse(polls$polldate==startdate | polls$polldate==enddate,3,1.5),shape=ifelse(polls$polldate==startdate | polls$polldate==enddate,23,21),color=paste0(col2,transp),fill=paste0(col2,transp))+
  geom_point(aes_string(x='polldate',y=party3),size=ifelse(polls$polldate==startdate | polls$polldate==enddate,3,1.5),shape=ifelse(polls$polldate==startdate | polls$polldate==enddate,23,21),color=paste0(col3,transp),fill=paste0(col3,transp))+
  geom_point(aes_string(x='polldate',y=party4),size=ifelse(polls$polldate==startdate | polls$polldate==enddate,3,1.5),shape=ifelse(polls$polldate==startdate | polls$polldate==enddate,23,21),color=paste0(col4,transp),fill=paste0(col4,transp))+
  geom_point(aes_string(x='polldate',y=party5),size=ifelse(polls$polldate==startdate | polls$polldate==enddate,3,1.5),shape=ifelse(polls$polldate==startdate | polls$polldate==enddate,23,21),color=paste0(col5,transp),fill=paste0(col5,transp))+
  # add trend lines
  # the "span" (smoothing parameter) should be manually changed for individual parties that have less polling data
  geom_smooth(aes_string(x='polldate',y=party1,color=shQuote('col1')),method="loess",span=spansize,n=nnum,se=FALSE)+
  geom_smooth(aes_string(x='polldate',y=party2,color=shQuote('col2')),method="loess",span=spansize,n=nnum,se=FALSE)+
  geom_smooth(aes_string(x='polldate',y=party3,color=shQuote('col3')),method="loess",span=spansize,n=nnum,se=FALSE)+
  geom_smooth(aes_string(x='polldate',y=party4,color=shQuote('col4')),method="loess",span=spansize,n=nnum,se=FALSE)+
  geom_smooth(aes_string(x='polldate',y=party5,color=shQuote('col5')),method="loess",span=spansize,n=nnum,se=FALSE)+
  scale_y_continuous(labels = function(x) paste0(x, "%"),limits=c(1,55))+    # add %, manual limits on y-axis
  scale_x_date(limits = as.Date(c(startdate,enddate)), date_minor_breaks = "1 months", date_breaks = "3 months", date_labels = "%b %Y")+    # grid: 1 month, labels: 3 months
  labs(x = "", y = "")+
  scale_color_manual(name="",
                     breaks = c('col1','col2','col3','col4','col5'),
                     labels = c(party1,party2,party3,party4,party5),
                     values = c('col1'=col1,'col2'=col2,'col3'=col3,'col4'=col4,'col5'=col5))+
  # legend appearance
  theme(
    axis.text.x = element_text(size = 11),
    axis.text.y = element_text(size = 12),
    axis.title.y = element_text(size = 16),
    legend.position="right",
    legend.key.width=unit(24, "pt"),
    legend.key.height=unit(24, "pt"),
    legend.text = element_text(size=16, margin = margin(b = 5, t = 5, unit = "pt")))

graph + theme()

ggsave(file="polls.svg", plot=graph, width=18, height=8)

# workaround since svglite doesn't properly work in Wikipedia
aaa=readLines("polls.svg",-1)
bbb <- gsub(".svglite ", "", aaa)
writeLines(bbb,"polls.svg")

polldate,ER,KPRF,LDPR,SRZP,NL
2024-06-16,48,8,8,3,3
2024-06-16,40.6,9.7,9,3.4,6.1
2024-06-09,51,7,8,2,2
2024-06-09,41.4,8.7,9.4,3.6,6.5
2024-06-02,47,8,10,2,3
2024-06-02,40.6,9.2,8.8,3.9,6.8
2024-05-29,46,9,8,2,3
2024-05-26,48,9,8,3,4
2024-05-26,40.3,9,9.4,3.7,6.6
2024-05-19,50,7,9,3,2
2024-05-19,40.2,8.7,9.5,3.6,6.5
2024-05-12,41.4,9.3,9.1,3.4,6.8
2024-05-05,49,7,8,2,4
2024-05-05,40.3,9.1,8.8,3.2,7.1
2024-04-28,50,7,8,3,4
2024-04-28,40.9,8.8,8.6,3.4,7.4
2024-04-21,46,8,8,3,4
2024-04-21,41.9,8.7,7.6,3.6,7.3
2024-04-14,54,6,8,2,3
2024-04-14,40.4,9,8.5,3.9,8.3
2024-04-07,50,7,8,3,4
2024-04-07,41.6,8.7,8.2,3.4,7.8
2024-03-31,54,7,6,2,3
2024-03-31,42.6,8.9,7.7,3,7.6
2024-03-27,47,10,7,3,4
2024-03-25,52,7,7,2,4
2024-03-24,41.6,9.4,7.9,3.3,8.3
2024-03-17,44,8.4,8.3,3.4,7.3
2024-03-10,51,6,9,3,4
2024-03-10,43.1,8.8,8.6,2.8,7
2024-03-03,53,7,8,2,3
2024-03-03,42.6,7.9,8.9,3.4,7.2
2024-02-28,48,9,7,3,4
2024-02-27,38,10,10,3,6
2024-02-25,48,8,10,2,4
2024-02-25,43.4,8.2,8.8,3.2,5.8
2024-02-18,52,7,7,3,4
2024-02-11,54,8,8,3,3
2024-02-11,42.7,8.8,8.3,3.6,5
2024-02-04,49,7,7,2,2
2024-02-04,42.7,8.5,8.2,3.7,5
2024-01-31,47,9,7,4,3
2024-01-28,48,9,8,4,3
2024-01-28,43.3,8.6,8.3,4,4.8
2024-01-21,49,8,7,4,2
2024-01-21,44.4,8.7,8.5,4,4.2
2024-01-19,35.1,8.6,11.8,4.2,8
2024-01-14,50,7,7,3,3
2024-01-14,43.7,7.7,8.7,3.7,4.6
2023-12-30,42.9,8.3,8,4.8,4.3
2023-12-24,49,7,7,2,2
2023-12-24,42.2,8.8,8.6,4.4,4.5
2023-12-17,48,7,8,3,2
2023-12-17,42,9.8,8.3,4.4,4.7
2023-12-10,47,9,7,3,2
2023-12-10,40.9,9.4,9.3,4.6,4.7
2023-12-03,47,8,11,4,3
2023-12-03,39.8,10.4,9.2,4.3,5
2023-11-29,42,9,8,4,3
2023-11-26,42,9,9,3,2
2023-11-26,40.9,9.2,9.2,4.4,4.4
2023-11-19,43,9,10,3,3
2023-11-19,39.8,9.9,8.8,4.9,4.8
2023-11-12,45,8,10,2,2
2023-11-12,40.1,10.1,9.5,4.6,4.5
2023-11-05,46,10,10,4,2
2023-11-05,39.4,9.6,9.5,4.5,4.8
2023-10-29,42,10,9,3,3
2023-10-29,39.1,10.2,9.2,4.4,5.1
2023-10-22,44,9,9,4,2
2023-10-22,39.6,9.9,9.5,5,4.5
2023-10-15,43,7,11,2,2
2023-10-15,40.8,9.9,9.2,4.9,4.4
2023-10-08,42,8,10,4,3
2023-10-08,39.2,10.6,9.8,4.8,4.2
2023-10-01,42,9,10,3,2
2023-10-01,38.5,10.5,9.5,5.1,4.7
2023-09-27,37,11,10,4,3
2023-09-24,41,8,12,4,3
2023-09-24,39.2,10.6,9,4.9,5.1
2023-09-17,41,8,9,3,3
2023-09-17,38.4,10.3,10,5.2,4.6
2023-09-10,43,9,10,4,3
2023-09-10,38,10.5,9.1,5,5
2023-09-10,32.3,11,13.4,7.3,8.3
2023-09-03,41,8,8,3,3
2023-09-03,37.6,11.1,9.6,5.1,4.4
2023-08-30,33,9,10,4,3
2023-08-27,43,8,9,3,3
2023-08-27,37.7,10.4,9.2,4.9,4.5
2023-08-20,39,8,10,3,2
2023-08-20,37.1,10.2,9.7,4.9,4.7
2023-08-13,44,9,10,4,2
2023-08-13,37.7,10.2,9,5,4.5
2023-08-06,39,10,9,3,3
2023-08-06,37.6,9.9,9.3,4.9,4.6
2023-07-30,41,8,9,4,3
2023-07-30,37.6,10.4,9.4,4.6,4.6
2023-07-23,41,9,8,3,3
2023-07-23,38.5,10,9.8,5.3,4.2
2023-07-16,43,10,10,4,3
2023-07-16,38.9,9.9,9.2,4.8,4.3
2023-07-09,42,9,9,3,2
2023-07-09,37.9,9.3,9.8,4.6,4.5
2023-07-02,41,8,11,3,2
2023-07-02,39,9.4,9,5,4.1
2023-06-28,39,8,9,4,3
2023-06-25,42,7,10,4,2
2023-06-25,37.9,10.4,9.2,5.6,4.3
2023-06-18,46,8,10,4,3
2023-06-18,39.3,10,8.6,5.8,4.4
2023-06-11,41,8,9,3,2
2023-06-11,38.6,10.2,9.5,5.3,4.3
2023-06-04,44,9,9,3,3
2023-06-04,37.7,10.1,9.5,5.7,4.3
2023-05-28,41,8,10,4,3
2023-05-28,37.9,10.5,9.3,5.8,4.4
2023-05-21,43,10,9,5,3
2023-05-21,37.9,10.4,9.4,5.7,4.7
2023-05-16,30.2,12.4,10.9,6.8,5.4
2023-05-14,44,9,9,3,2
2023-05-14,39.3,10.4,9.3,5.9,4.1
2023-05-07,39.4,10.8,9.6,5.4,4.1
2023-04-30,44,8,9,4,3
2023-04-30,39,10.2,9.3,5.6,4.3
2023-04-26,39,10,9,5,3
2023-04-23,46,9,10,4,2
2023-04-23,37.6,10.7,9.5,5.7,4.6
2023-04-16,42,8,9,3,2
2023-04-16,39,10.2,9.3,5.2,4.3
2023-04-09,42,8,10,3,2
2023-04-09,39.8,10.3,8.9,5.5,4.7
2023-04-02,45,10,8,3,3
2023-04-02,40.3,9.9,8.3,5.7,4.7
2023-03-29,39,10,7,4,3
2023-03-26,47,9,9,4,3
2023-03-26,38.8,10.5,8.8,5.6,4.4
2023-03-19,45,9,9,4,2
2023-03-19,39.4,10.7,9,5.5,4.4
2023-03-12,44,10,8,3,3
2023-03-12,39.5,10.6,8.4,5.6,4.8
2023-03-05,45,9,7,3,3
2023-03-05,38.8,10.3,8.7,5.3,4.4
2023-02-26,47,9,9,5,2
2023-02-26,39.2,10.5,8.2,5.6,4.9
2023-02-19,43,10,8,3,3
2023-02-19,39.1,10.8,8.8,5.7,4.7
2023-02-12,40,10,7,3,3
2023-02-12,38.6,10.5,8.5,5.3,4.6
2023-02-05,41,9,8,4,3
2023-02-05,37.7,10.9,8.9,5.2,4.5
2023-01-31,37,9,8,5,4
2023-01-29,44,8,10,5,3
2023-01-29,38.4,10.2,8,6,4.4
2023-01-22,44,8,8,3,2
2023-01-22,38.7,11,9.1,5.2,4.6
2023-01-15,42,7,9,3,2
2023-01-15,38.8,10.6,9.2,5.7,3.9
2022-12-30,38.4,10.4,9.3,5.7,4.1
2022-12-25,44,10,8,4,2
2022-12-25,37.2,10.8,9.2,5.7,4.6
2022-12-18,41,9,11,4,3
2022-12-18,37.3,11,9.6,5.4,4.6
2022-12-11,41,9,8,5,2
2022-12-11,37.9,10.3,8.3,5.9,4.6
2022-12-04,42,9,10,3,3
2022-12-04,37.7,10.7,8.5,6.2,4.9
2022-11-30,36,11,8,4,4
2022-11-27,43,9,7,3,3
2022-11-27,38.2,10.4,8.5,6,4.9
2022-11-20,43,9,8,4,3
2022-11-20,38.8,10.7,8.9,5.6,4.7
2022-11-13,42,9,9,4,2
2022-11-13,38.5,10.4,8.9,5.6,4.6
2022-11-06,44,9,8,4,2
2022-11-06,40.4,10.3,8.1,5.4,4.7
2022-10-30,41,9,8,4,3
2022-10-30,40.3,9.9,8.9,6.1,4.2
2022-10-23,43,9,8,4,2
2022-10-23,40.6,11.1,8.6,5.9,4.5
2022-10-16,47,8,8,3,2
2022-10-16,41,10.1,8.2,5.8,4.8
2022-10-09,43,10,8,5,3
2022-10-09,41,10.1,9.1,5.3,4.3
2022-10-02,46,8,8,3,3
2022-10-02,41.6,10,8.6,5.6,4.1
2022-09-28,36,11,9,4,3
2022-09-25,41,9,7,4,3
2022-09-25,40.9,11,8.1,5.8,4
2022-09-18,42,9,8,3,3
2022-09-18,41,10.9,7.8,5.5,4.2
2022-09-11,43,10,10,4,3
2022-09-11,40.7,10.3,7.5,5.8,4.1
2022-09-04,40,10,9,3,3
2022-09-04,39.4,10.3,8.3,6.2,4.2
2022-08-28,41,10,7,4,2
2022-08-28,40.2,10.2,8.1,5.7,4.8
2022-08-21,40,10,8,4,2
2022-08-21,39.9,10.7,8.6,5.4,4.3
2022-08-14,44,10,10,4,2
2022-08-14,40,11.3,7.8,5.4,4.4
2022-08-07,42,10,8,4,3
2022-08-07,40.7,10.8,7.5,5.7,4.2
2022-07-31,42,8,8,4,3
2022-07-31,40.3,10.6,7.9,5.5,4.4
2022-07-27,40,10,8,5,3
2022-07-24,41,9,8,3,4
2022-07-24,41.4,10.3,7.5,5.8,4.3
2022-07-17,45,10,8,4,2
2022-07-17,40,10.8,7.6,5.8,4.4
2022-07-10,44,11,8,4,3
2022-07-10,40.5,11.3,8.2,5.7,4.5
2022-07-03,42,9,8,3,3
2022-07-03,40.6,10.8,7.8,5.3,4.4
2022-06-29,38,11,9,4,4
2022-06-26,42,11,8,4,2
2022-06-26,41,11.1,7.9,5.6,4.9
2022-06-19,44,9,8,4,3
2022-06-19,41.6,10.2,7.6,5.7,4.7
2022-06-12,44,10,9,3,2
2022-06-12,40.9,10.7,8.5,6.5,5
2022-06-05,44,10,8,4,3
2022-06-05,41.7,10.4,7.9,5.7,4.7
2022-05-31,38,11,7,4,4
2022-05-29,41,10,10,3,3
2022-05-29,40.7,10.9,8,5.9,4.7
2022-05-22,46,10,10,5,2
2022-05-22,41.2,11.2,8.4,5.7,4.5
2022-05-15,41,9,9,4,3
2022-05-15,40.5,10.7,8.7,5.6,4.6
2022-05-08,39.9,11.3,8.7,5.3,4.9
2022-05-01,42,9,11,3,3
2022-05-01,41.2,11.2,8.5,5.9,4.8
2022-04-27,40,10,8,4,5
2022-04-24,45,10,9,4,3
2022-04-24,40.6,11.4,8.9,5.2,4.5
2022-04-17,45,9,9,4,2
2022-04-17,40.4,10.3,9.4,5.8,5
2022-04-10,42,8,11,5,2
2022-04-10,42.5,11.1,8.8,5.6,4.8
2022-04-03,44,9,8,4,3
2022-04-03,42.2,11.2,7.7,5.4,4.4
2022-03-30,39,11,9,5,4
2022-03-27,45,10,8,5,3
2022-03-27,41,11.2,8.5,5.8,4.6
2022-03-20,43,11,8,4,3
2022-03-20,41.8,11.1,7.9,5.4,4.9
2022-03-13,41,10,8,3,3
2022-03-13,40,11.8,7.2,6.3,5.2
2022-03-06,44,10,8,3,3
2022-03-06,39.4,11.7,7.4,5.2,5.1
2022-02-27,41,12,7,5,4
2022-02-27,36,13,7.2,5.8,5.9
2022-02-21,31,13,8,5,4
2022-02-20,32,14,8,4,5
2022-02-20,30.3,16,7.2,6.5,6.9
2022-02-13,31,14,8,4,5
2022-02-13,30.6,15.7,7.7,6.6,7.1
2022-02-06,33,14,8,5,5
2022-02-06,30.6,15.3,8.2,6.2,7.1
2022-01-30,34,15,8,6,5
2022-01-30,30.7,15.6,7.8,6.5,6.7
2022-01-23,34,15,8,6,5
2022-01-23,30.7,15.6,7.8,6.5,6.7
2022-01-23,32,15,9,5,4
2022-01-23,30.6,16.3,8,6.4,7.2
2022-01-16,31,13,9,4,4
2022-01-16,31.1,16.6,7.2,6.6,7.3
2021-12-30,30.5,17.4,6.9,6.9,7.2
2021-12-26,30,15,7,5,5
2021-12-26,29.8,18.1,7.5,7,7.4
2021-12-22,27,15,8,5,5
2021-12-19,31,15,7,5,5
2021-12-19,29.5,17.9,7.1,6.7,7.7
2021-12-12,32,15,8,5,6
2021-12-12,27.7,18.1,7.4,6.5,7.9
2021-12-05,32,16,9,5,6
2021-12-05,28.3,18.2,7.7,6.9,8.6
2021-12-01,26,13,8,4,5
2021-11-28,31,15,9,5,6
2021-11-28,28.6,18,7.8,6.9,8.1
2021-11-21,30,15,8,5,6
2021-11-21,29.2,18.6,7.6,6.9,8.2
2021-11-14,30,15,9,5,6
2021-11-14,28.9,18.7,7.9,6.5,8.1
2021-11-07,31,15,10,6,7
2021-11-07,30.2,17.7,7.4,6.6,7.8
2021-10-31,31,16,9,6,6
2021-10-31,28.6,19.4,8.1,7.1,8.7
2021-10-27,29,14,8,5,5
2021-10-24,29,17,8,6,6
2021-10-24,29.8,19.4,7.3,6.9,8.5
2021-10-17,30,18,9,6,6
2021-10-17,30.1,19.8,7.7,6,8.6
2021-10-10,29.8,20.2,7.5,6.3,8.6
2021-10-03,29.8,20.2,7.3,6.1,8.4
2021-09-26,29.5,23.3,7.6,6.4,8.4
2021-09-19,49.82,18.93,7.55,7.46,5.32