A simple R ggplot of percent positive of covid cases by USA State.

covid19-state-ratio.R

library("ggplot2")
dataUrl <- "https://covidtracking.com/api/states/daily.csv"
c <- read.csv(dataUrl)
c$date <- as.Date(as.character(c$date), format = "%Y%m%d")
c_tmp <- c[order(c[c$date == max(c$date), ]$total, decreasing = TRUE), ]
states <- c_tmp[c_tmp$date == max(c_tmp$date), ]$state[1:10]
c[is.na(c$pending), ]$pending <- 0
c$ratio <- (c$positive / (c$total - c$pending))
c <- c[c$state %in% states, ]
g <- ggplot(c, aes(x = date, y = ratio))
g <- g + labs(title = "Percent of COVID-19 Positive Cases Out of Total Tested",
              subtitle = "(Top 10 states with the most tests conducted)",
              caption = "Pending Tests Excluded.")
g <- g + xlab("Date") + ylab("Percent Tested Positive")
g <- g + geom_line(aes(color = state))
g <- g + geom_label(aes(fill = factor(state), label = state),
                    position = position_jitter(width = .2, height = 0.01),
                    colour = "white",
                    size = 2)
g <- g + scale_y_continuous(labels = function(x) {
    paste(round(x * 100), "%", sep = "")
})
g <- g + theme(legend.position = "none")
(g)
## ggsave("covid.png")

Downloads live data at runtime and makes a chart like this.

March 31st.