Density timeline graph

Question

I'd love to make a timeline density graph like the New York Times does for COVID-19 cases (screenshot below). I am trying to do it with crime data instead of COVID data. Any ideas on how to use R (ggplot2, plotly, etc) to make a graph like this that shows density by day? So far, I haven't found a similar style in the R-graph Gallery. Thanks.

update: Here is the closest approximation I have come up with so far:

dat_c_grp <- dat_c %>% 
        group_by(report_date, month) %>% 
        summarize(count = n())
p <- ggplot(dat_c_grp, aes(report_date, month, fill = count))+
        geom_tile(color= "white",size=0.1) + 
        scale_fill_viridis(name="Daily",option ="C")

output:

p

I'd like the months collapsed the months into one row. I can't figure out how to make it all one row.

Answer 1

Thanks to both Allan Cameron and Konrad Rudolph.

Here is the code to answer my question:

dat_c_grp <- dat_c %>% 
    count(report_date, month, name = 'count')

p <- ggplot(dat_c_grp, aes(report_date, 0, fill = count))+
    geom_tile(color= "white",size=0.1) + 
    scale_fill_gradientn(colors = c("#f3df8e", "#fdad45", "#ff700a", "#cc0a06"))+
    removeGrid()+
    theme(panel.spacing = unit(50, "points"),
          legend.position = "top",
          axis.title.y = element_blank(),
          axis.text.y = element_blank(),
          axis.ticks.y=element_blank(),
          strip.text = element_blank(),
          panel.grid = element_blank())
p

And output:

Answer 2

Here's a full reprex of one way to do this which emulates the look of the original fairly well (obviously I've had to make the data up):

library(ggplot2)

set.seed(1)

Dates  <- rep(seq(as.Date("2020-03-01"), by = "1 week", length.out = 36), 3)
Places <- rep(c("Conneticut", "Fairfield", "New Haven"), each = 36)
Cases  <- as.numeric(replicate(3, rpois(36, dgamma((1:36)/3, 2.5) * 100))) +
          as.numeric(replicate(3, rpois(36, 0.0002 * exp(1:36)^(1/3))))

df <- data.frame(Dates, Places, Cases)

ggplot(df, aes(Dates, Places, fill = Cases)) + 
  geom_tile(color = "gray92") +
  facet_grid(Places~., scales = "free_y") +
  scale_fill_gradientn(colors = c("#f3df8e", "#fdad45", "#ff700a", "#cc0a06")) +
  theme_minimal() +
  scale_x_date(date_breaks = "month", labels = scales::date_format("%b")) +
  theme(panel.spacing = unit(50, "points"),
        legend.position = "top",
        axis.title.y = element_blank(),
        strip.text = element_blank(),
        panel.grid = element_blank())