CODEWITHSUNDEEP
rloopsggplot2
user4883351
user4883351

Reputation:

Export a series of plots created by looping through a list of variables (in R)

The dataset I'm working with has about 300 variables. I would like to create a subset of variables(just in a list) and use that list to create and export a histogram for each variable with that variable name. I am using ggplot2.

So far I have:

variables = c("race","gender") #my list of variables to be used

for(i in 1:2){
#creates the name for the plot
  jpeg(file=paste("myplot_", variables[i], ".jpg", sep="")) 
#creates and saves the plot 
  print(qplot(variables[i], data=mydata, geom = "histogram"))
  dev.off()
}

Right now it is creating the graph, but it's just a big box and doesn't seem to be reading the variable from the dataset (mydata)

Thanks for any help. I've seen some other posts similar, but haven't been able to work it out. Mark

Upvotes: 0

Views: 114

Answers (2)

zach
zach

Reputation: 30983

Here is an annotated example that uses ggsave and aes_string. Its a little longer than your example but relatively straightforward to follow.

 #load ggplot
 library(ggplot2)

 #make some data
 df <- data.frame(race=c(1,2,3),
                  gender=c(4,5,6), 
                  country=c("USA","Canada","Mexico"))

# write a function to make a plot
# note the ggsave and aes_string functions 
makeplot <- function(df,name){
     title <- paste0("myplot_",name,".jpg")
     p     <- ggplot(data= df,aes_string(x=name)) + 
                geom_histogram()
     ggsave(p, file=title)
 }

 # make your vector of column headings
 varlist = c('race','gender')

 # run your function on each column heading
 for (var in varlist) makeplot(df,var)

Upvotes: 0

user4883351
user4883351

Reputation:

Out of sheer dumb luck, this seems to be working. Is there a better way to do this?

variables = c("race","gender")

for(Var in variables){
  jpeg(file=paste("myplot_", Var, ".jpg", sep=""))
  print(qplot(mydata[,Var], data=mydata, geom = "histogram"))
  dev.off()
}

Upvotes: 1

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