JTBC 2017-02-16

Problem

JTBC 정치부회의에서는 다음과 같은 도표의 민주당 지지자 중 후보지지도 여론조사 결과를 보도.

JTBC 정치부회의 2017. 2월

막대의 높이에 의구심을 표한 시청자들의 항의에 직면함.

제대로 된 막대그래프를 그리면서 R Base plot과 ggplot에 대하여 학습.

Data Setup

library(magrittr)
candidates <- c("문재인", "안희정", "이재명", "안철수", "황교안")
candidates %<>% factor(levels = candidates)
week2 <- c(57, 20, 11, 2, 1)
week3 <- c(61, 24, 7, 1, 1)
rates_df <- data.frame(candidates, week2, week3, 
                       stringsAsFactors = FALSE)
rates_df

##   candidates week2 week3
## 1     문재인    57    61
## 2     안희정    20    24
## 3     이재명    11     7
## 4     안철수     2     1
## 5     황교안     1     1

Barplot(R Base)

par(family = "KoPubWorldDotum Medium")
b1 <- barplot(t(as.matrix(rates_df[, 2:3])), 
              axes = FALSE, 
              ylim = c(0, 65), 
              beside = TRUE, 
              names.arg = rates_df[, 1], 
              legend.text = c("2주차", "3주차"), 
              col = c("darkgrey", "blue"))
# axis(side = 2, 
#     at = as.vector(as.matrix(rates_df[, 2:3])), 
#     labels =  as.vector(as.matrix(rates_df[, 2:3])), las = 1)
text(x = b1[1, ], 
     y = week2 + 2, 
     labels = week2, 
     col = "darkgrey")
text(x = b1[2, ], 
     y = week3 + 2, 
     labels = week3, 
     col = "blue")
main_title <- "대선후보 지지도(%)"
sub_title <- "JTBC 정치부회의, 한국갤럽 2017. 2월 7-9일, 14-16일"
main_text <- "지지정당 : 더불어민주당"
title(main = main_title, 
      sub = sub_title, 
      cex.main = 2)
text(x = 8, y = 60, 
     main_text, 
     cex = 1.2)
box(which = "figure", lwd = 3)

dev.copy(png, "../pics/jtbc170216.png", width = 640, height = 320)

## quartz_off_screen 
##                 3

dev.off()

## quartz_off_screen 
##                 2

ggplot

Data for ggplot()

library(reshape2)
# (rates_df$candidates_f <- factor(candidates, 
#                                 levels = candidates))
str(rates_df)
(rates_df_melt <- melt(rates_df, 
                      id.vars = "candidates", 
                      measure.vars = c("week2", "week3"), 
                      variable.name = "week", 
                      value.name = "rates"))
str(rates_df_melt)

library(tidyverse)

## ── Attaching packages ─────────────────────────────────────────── tidyverse 1.2.1 ──

## ✔ ggplot2 3.1.1       ✔ purrr   0.3.2  
## ✔ tibble  2.1.1       ✔ dplyr   0.8.0.1
## ✔ tidyr   0.8.3       ✔ stringr 1.4.0  
## ✔ readr   1.3.1       ✔ forcats 0.4.0

## ── Conflicts ────────────────────────────────────────────── tidyverse_conflicts() ──
## ✖ tidyr::extract()   masks magrittr::extract()
## ✖ dplyr::filter()    masks stats::filter()
## ✖ dplyr::lag()       masks stats::lag()
## ✖ purrr::set_names() masks magrittr::set_names()

rates_tbl <- rates_df %>%
  as_tibble %>%
  gather(key = "week", value = "rates", - candidates) 
str(rates_tbl)

## Classes 'tbl_df', 'tbl' and 'data.frame':    10 obs. of  3 variables:
##  $ candidates: Factor w/ 5 levels "문재인","안희정",..: 1 2 3 4 5 1 2 3 4 5
##  $ week      : chr  "week2" "week2" "week2" "week2" ...
##  $ rates     : num  57 20 11 2 1 61 24 7 1 1

geom_bar()

# library(ggplot2)
source("theme_kr.R")
g0 <- ggplot(data = rates_tbl, 
             mapping = aes(x = candidates, 
                           y = rates, 
                           fill = week)) 
(g1 <- g0 + 
  geom_bar(stat = "identity", 
           position = position_dodge())) 

(g2 <- g1 +
  geom_text(mapping = aes(x = candidates, 
                          y = rates + 2, 
                          label = rates,
                          colour = week), 
            position = position_dodge(width = 1), 
            size = 5))

(g3 <- g2 +
  theme_bw() +
  theme_kr)

(g4 <- g3 + 
    scale_fill_manual(name = "", 
                      values = c("darkgrey", "blue"), 
                      labels = c("2월 2주차", "2월 3주차")) +
    scale_colour_manual(name = "",
                        values = c("darkgrey", "blue"), 
                        labels = c("2월 2주차", "2월 3주차")))

(g5 <- g4 + 
    scale_x_discrete(name = "대선후보"))

(g6 <- g5 +
    scale_y_continuous(name = "지지도", 
                       breaks = as.vector(as.matrix(rates_df[, 2:3])), 
                       labels = as.vector(as.matrix(rates_df[, 2:3]))))

(g7 <- g6 +
    labs(title = main_title, 
         subtitle = sub_title))

(g8 <- g7 +
  theme(plot.title = element_text(hjust = 0.5), 
        plot.subtitle = element_text(family = "KoPubWorldDotum Medium"),
        legend.position = c(0.9, 0.7)))