Visualisasi Data - Barchart

Kegunaan Barchart

Barchart menunjukkan hubungan antara variabel numerik dan kategorik. Setiap entitas dari variabel kategori direpresentasikan sebagai batang (bar).

Barchart digunakan untuk :
1. Membandingkan variabel
2. Menampilkan data kategorikal
3. Visualisasi data diskrit

Visualisasi kali ini yaitu barchart menggunakan library ggplot2.

Data yang digunakan diperoleh dari https://www.kaggle.com/datasets/arnabchaki/data-science-salaries-2023

Library

library(readxl)
library(ggplot2)

Import Dataset

data <- read_excel("D:/CHISTAT LEARNING/R SERIES/DATASET/ds_salaries.xlsx", col_names=TRUE)

experience_counts <- table(data$experience_level)
experience_counts

## 
##   EN   EX   MI   SE 
##  320  114  805 2516

Membuat bar chart satu warna

experience_counts <- table(data$experience_level)

ggplot(data = data, aes(x = experience_level)) +
  geom_bar(fill = "pink") +
  labs(title = "Jumlah Experience Level",
       x = "Experience Level",
       y = "Jumlah") +
  theme_minimal() +
  theme(axis.text.x = element_text(angle = 0, hjust = 1))

Membuat barchart custom warna

colors <- c("#58BECA", "#FE74BB", "#5BCEAC", "#EADA62")

ggplot(data = data, aes(x = experience_level, fill = experience_level)) +
  geom_bar() +
  geom_text(aes(label=after_stat(count)), stat='count', vjust=1.0, size=3) +
  scale_fill_manual(values=colors)+
  labs(title = "Jumlah Data Scientist Berdasarkan Tingkat Pengalaman Kerja",
       x = "Tingkat Pengalaman Kerja",
       y = "Jumlah") +
  theme_minimal() +
  theme(axis.text.x = element_text(angle = 0, hjust = 1),
        legend.position = "none",
        plot.title=element_text(hjust=0.5, size=12, face='bold'),
        axis.title.x=element_text(size=10, face="bold"),
        axis.title.y=element_text(size=10, face="bold"))

        #panel.grid=element_blank(),
       #plot.background=element_rect(fill="gray90"))

Grouped Chart

colors <- c("#58BECA", "#FE74BB", "#5BCEAC", "#EADA62")

ggplot(data, aes(x = work_year, fill = experience_level)) +
  geom_bar(stat = "count", position = "dodge") +
  scale_fill_manual(values = colors) +
  labs(title = "Jumlah Data Scientist Berdasarkan Tingkat Pengalaman Kerja di Setiap Tahun",
       x = "Tahun",
       y = "Jumlah",
       fill="Tingkat Pengalaman Kerja") +
  theme_minimal()+
  theme(axis.text.x = element_text(angle = 0, hjust = 1),
        plot.title=element_text(hjust=0.5, size=12, face="bold"),
        axis.title.x=element_text(size=8, face="bold"),
        axis.title.y=element_text(size=8, face="bold"),
        legend.text = element_text(size = 8), #font teks legend
        legend.title = element_text(size = 8)) #font judul legend

Stacked-Bar Chart

colors <- c("#58BECA", "#FE74BB", "#5BCEAC", "#EADA62")

ggplot(data, aes(x = work_year, fill = experience_level)) +
  geom_bar(stat = "count", position = "stack") +
  scale_fill_manual(values = colors) +
  labs(title = "Jumlah Data Scientist Berdasarkan Tingkat Pengalaman Kerja di Setiap Tahun",
       x = "Tahun",
       y = "Jumlah",
       fill="Tingkat Pengalaman Kerja") +
  theme_minimal()+
  theme(axis.text.x = element_text(angle = 0, hjust = 1),
        plot.title=element_text(hjust=0.5, size=12, face="bold"),
        axis.title.x=element_text(size=8, face="bold"),
        axis.title.y=element_text(size=8, face="bold"),
        legend.text = element_text(size = 8), #font teks legend
        legend.title = element_text(size = 8, face="bold")) #font judul legend