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iterative loop with user input?

4 messages · Christopher Marcum, jim holtman, Bart Joosen

#
Hello R-Users,

I would like to use an iterative loop to collect user input from within a
function. I'm sure that this would be some combination of "for","break",
and "next" but have not been able to get the syntax down.

I would like to print some text to the screen at each step in the loop,
ask the user for input which is saved in an object, and then advance the
loop.

Here is an example:

#anchor is a file with unique ids
anchor<-rep(1:30)
anchor<-paste(anchor,"uid",sep="")

#codelist is where I would like to store user input
codelist<-NULL

for(i in 1:30) {
#tell the user which ID is being coded
print(paste("You are coding unique ID",anchor[i],sep=":   "))
#Read a line from a text file:
print(readLines(file="file_with_30_lines.txt",warn=F)[i])
#Ask the user for input
codelist[i]<-readline(paste("Select one of the following: \n \t please
enter 1, 2, or 3: \n Enter Your Response HERE:   ",sep=""))
}

Ideally, loop should work from inside a function.

Any tips? Thanks in advance for your time and patience.

Best,
Chris Marcum
Sociology/Cal(it)^2
University of California-Irvine
#
Is this what you want to do:
+     x <- list()
+     for (i in 1:10){
+         z <- readline(paste("Parameter ", i, ": ", sep=''))
+         # just store the input in a list with the same key
+         x[[z]] <- z
+     }
+     x
+ }
Parameter 1: 12
Parameter 2: 2
Parameter 3: asdf
Parameter 4: 33
Parameter 5: scs
Parameter 6: sdaf2
Parameter 7: 234
Parameter 8: gfd
Parameter 9: 123
Parameter 10: aa
$`12`
[1] "12"

$`2`
[1] "2"

$asdf
[1] "asdf"
On Thu, Apr 3, 2008 at 1:18 PM, Christopher Marcum <cmarcum at uci.edu> wrote:

  
    
#
Your example runs fine at my pc, except from the readLines("File with 30
....) part.

But this is probably a striped code, so maybe you should take a look at
flush.console().

Bart
Christopher Marcum wrote:

  
    
#
Hi All,

Thank you for your solutions. They all seem reasonable and I will be
testing these out later this evening. I'm replying to the list because I
think these solutions will come in handy to those using R as a programming
language.


-Chris Marcum
Sociology/Cal(it)^2
University of California - Irvine
Phil Spector wrote:

            

        
jim holtman wrote: