#collapse-hide

suppressPackageStartupMessages(library(tidyverse))

theme_set(theme_minimal(base_size = 20))

# Abaikan kompleksitas kode dalam membuat term-nya, saya sedang latihan R
df <- tibble(
    term = head(
        sort(c(outer(
            paste(2013:2017, 2014:2018, sep = "/"),
            c('term 1', 'term 2'),
            FUN = paste,
            sep = "\n"
        ))),
        -1
    ),
    mean_year = c(4, 4.5, 4.03, 4.06, 4.14, 4.21, 4.03, 4.5, 4.4),
    gpa = c(3.41, 3.32, 3.51, 3.53, 3.41, 3.45, 3.42, 3.25, 3.34)
)

par(mfrow = c(2, 1))
with(df, {
    barplot(
        mean_year ~ term,
        main = 'Length of Study',
        xlab = 'Graduation year',
        ylab = 'Year to graduate'
    )
    barplot(
        gpa ~ term,
        main = "Average Graduates' GPA",
        xlab = "Graduation year",
        ylab = "GPA"
    )
})

#collapse-hide

options(repr.plot.width = 13, repr.plot.height = 8, repr.plot.res = 100)

df %>%
    rename(
        GPA = gpa,
        `Year to graduate` = mean_year
    ) %>%
    pivot_longer(-(term)) %>%
    ggplot(aes(group = 1)) +
    geom_line(aes(x = term, y = value), size = 1) +
    labs(x = "Graduation year", y = "") +
    facet_grid(name ~ ., scales = 'free_y') +
    theme_classic(base_size = 20)