Parsing R user input into plotting functions

Question

I've been dealing with user input for various graphs. My main aim was to ask the user for an input and then parse this to a plotting function. I managed to do this for scatterplot, but not boxplot and barplot. This is my working example:

n<- function(){
    readline(prompt="enter x value to plot: ")
}

m<- function(){
    readline(prompt="enter y value to plot: ")
}

plotfun <- function(dat) {
    colx <- n()
    coly <- m()
    plot(dat[,colx], dat[,coly], main="Scatterplot", pch=20,xlab=[,colx] )      
}

But when I try something similar with boxplot for example:

plot2<-function(infile){
    a<-readline(prompt="which variable")
    barplot(table(infile$a))
}

or

a<-readline(prompt="enter...")
Boxplot( ~ a, data=infile, id.method="y")

It doesn't work

Errors were something like: can't find the object, argument "infile" is missing, with no default.

Where does the Boxplot function come from?

MrFlick
– MrFlick

2014-05-28 05:42:38 +00:00
Commented May 28, 2014 at 5:42 — MrFlick
– MrFlick, Commented May 28, 2014 at 5:42
@MrFlick car::Boxplot

James King
– James King

2014-05-28 05:50:33 +00:00
Commented May 28, 2014 at 5:50 — James King
– James King, Commented May 28, 2014 at 5:50

Robert Krzyzanowski · Accepted Answer · 2014-05-28 05:31:36Z

1

What is infile?

plot2 <- function(){
  a <- readline(prompt = "which variable")
  barplot(table(a))
}

answered May 28, 2014 at 5:31

Robert Krzyzanowski

9,35431 silver badges24 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

sdgaw erzswer Over a year ago

infile is for example a CSV file in which there is the variable I would want to plot

sdgaw erzswer Over a year ago

I've tried this script you provided and it doesn't work, it plots something, but it is of no use. (everything colored in barplot, just a line in Boxplot.

MrFlick · Accepted Answer · 2014-05-28 05:42:47Z

0

You cannot use "$" with character variable names. You must do the subsetting with [ as you did in the other cases

plot2<-function(infile){
    a<-readline(prompt="which variable")
    barplot(table(infile[,a]))
}

If your Boxplot function is the one from car, then

a<-readline(prompt="enter...")
Boxplot(infile[,a], labels=rownames(infile), id.method="y")

Is the variable friendly equivalent. You can't use character variables in formulas either. They are taken as literal values.

answered May 28, 2014 at 5:42

MrFlick

209k19 gold badges300 silver badges324 bronze badges

2 Comments

sdgaw erzswer Over a year ago

Darn, i knew something was wrong.There is one more thing, when I try this while having my dataset imported in R as infile, it says there is infile missing? how is this possible? I am doing my work in Rcmdr, is this important? edit: It works perfectly now. Thank you kind sir.

MrFlick Over a year ago

@user3523464 It's unclear from your description what the error might me. Is it the variable infile is missing or is the problem when you are trying to read the data that it's not there? Make sure you have the right path. But if you have a new problem, it's best to ask a new question.

Collectives™ on Stack Overflow

Parsing R user input into plotting functions

2 Answers 2

2 Comments

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related