Plotting data in R - ggplot or other plot-CodePudding

I am working on a project with Covid data, and I wish to plot (and later compare) covid data from three countries: Netherlands, Germany, France all on the same plot.

I wish to name the x-axis "Date", the y-axis "Number of confirmed cases" and the title of the legend "COVID Cases in Countries".

So far, I have created a final data frame with the data from all three counties called "dfFinal". The ggplot I included does not work (because I dont know how to code it). I am just having trouble plotting the information. Could someone help? The data has been gathered an read using Jsonlite, and is easily re-created without needing a data-set.

structure(list(Country = c("Netherlands", "Netherlands", "Netherlands", "Netherlands", "Netherlands", "Netherlands", "Netherlands", "Netherlands", "Netherlands", "Netherlands", "Netherlands", "Netherlands", "Netherlands", "Netherlands", "Netherlands"), Date = structure(c(18317, 18318, 18319, 18320, 18321, 18322, 18323, 18324, 18325, 18326, 18327, 18328, 18329, 18330, 18331), class = "Date"), Cases = c(0L, 1L, 6L, 10L, 18L, 24L, 38L, 82L, 128L, 188L, 265L, 321L, 382L, 503L, 603L)), row.names = 36:50, class = "data.frame")

install.packages("jsonlite", dependencies = TRUE)
library("jsonlite")

tmp <- readLines("https://pomber.github.io/covid19/timeseries.json")
jsonLot <- fromJSON(tmp)

myjsonLot <- toJSON(jsonLot, pretty=TRUE)
fileConn <- file(paste0("Covid19_timeseries.json"))
writeLines(myjsonLot, fileConn)


dfN <- data.frame(Country = c("Netherlands"), Date = c(jsonLot$Netherlands$date), Cases = 
c(jsonLot$Netherlands$confirmed))
dfN[,]

dfG <- data.frame(Country = c("Germany"), Date = c(jsonLot$Germany$date), Cases = 
c(jsonLot$Germany$confirmed))
dfG[,]

dfF <- data.frame(Country = c("France"), Date = c(jsonLot$France$date), Cases = 
c(jsonLot$France$confirmed))
dfF[,]

dfFinal <- rbind.fill(dfN, dfG, dfF)
View(dfFinal)

ggplot(dfFinal, aes(x=Date, y=Cases)   geom_line(size=1)  
xlab("Date")   ylab("Number of confirmed cases")   scale_x_datetime(breaks = "1 day")  
geom_line(aes(y=dfN$Cases), colour ="red")  
geom_line(aes(y=dfG$Cases), colour ="red")  
geom_line(aes(y=dfF$Cases), colour ="red"))

CodePudding user response：

Your code does not work, because you are supposed to add other calls like geom_line() or xlab() to ggplot() outside, not inside. I fixed it:

dfFinal$Date <- as.POSIXct(dfFinal$Date)

ggplot(dfFinal, aes(x=Date, y=Cases, group=Country))   
  geom_line(size=1)  
  xlab("Date")   
  ylab("Number of confirmed cases")   
  scale_x_datetime(breaks = "1 day")

I also added transformation of the Date variable, because when you read JSON it is not in a proper format.

However, your style of code is not very great. I recreated rest of your data transformation in a way which is more compliant with tidy R code standards.

library(jsonlite)
library(dplyr)  # for data transformation and piping
library(purrr)  # for mapping and binding
library(ggplot2)

# combine function calls by piping them, see help for `%>%` for details
dat <- readLines("~/../Desktop/timeseries.json") %>% fromJSON() 

# for each of the data frames in the json append the name of the data.frame as 
# "Country" variable and then bind all of them 
dat <- imap_dfr(dat, ~ .x, .id = "Country") %>%
  mutate(Date = as.POSIXct(date)) %>% # transform date into a proper format
  filter(Country %in% c("Netherlands", "France", "Germany")) # filter data by focus countries

ggplot(dat, aes(x = Date, y = confirmed, group = Country, color = Country))   
  geom_line(size=1)  
  ggtitle("Number of COVID-19 casses in selected countries")  
  xlab("Date")   
  ylab("Number of confirmed cases")