iri_monthly %>%
filter(date >= as.Date("2022-03-01")) %>%
group_by(variable) %>%
arrange(date) %>%
mutate(index = 100*cumprod(1+value/100)) %>%
ungroup %>%
add_row(date = as.Date("2022-02-01"), variable = "Total", index = 100) %>%
add_row(date = as.Date("2022-02-01"), variable = "MN", index = 100) %>%
add_row(date = as.Date("2022-02-01"), variable = "MDD", index = 100) %>%
add_row(date = as.Date("2022-02-01"), variable = "PPX", index = 100) %>%
left_join(variable, by = "variable") %>%
ggplot + geom_line(aes(x = date, y = index, color = Variable)) +
theme_minimal() + xlab("") + ylab("Prix en supermarché (Février 2022 = 100)") +
scale_x_date(breaks = seq.Date(as.Date("2019-11-01"), as.Date("2024-01-01"), "1 month"),
labels = scales::date_format("%b %y")) +
scale_y_continuous(breaks = seq(-100, 200, 5)) +
theme(legend.position = c(0.3, 0.8),
axis.text.x = element_text(angle = 45, vjust = 1, hjust = 1),
legend.title = element_blank())
