[R] If (x > 0)

[Henrik Bengtsson]

Try adding --vanilla when calling R, e.g.

R --vanilla --no-save --args 5 < test1.R

because I think you're picking up and previously stored session.
You'll most likely will find that "res <- conditional1(x)" will give
an error saying 'conditional1' is not defined; you need to define the
function before using it.

My $.02

/H

On Mon, Feb 13, 2012 at 1:59 PM, Schmidt, Michael
<MSchmidt at med.miami.edu> wrote:
> Hi,
> I am new to R. I was trying to get a very simple program to run. Take one number from the command line. If the number < 0 return -1. If number > 0 return 1 and if the number == 0 return 0. The code is in a file called test1.R
>
>
> The code:
>
> #useage: R --no-save --args 5 < test1.R
> args = (commandArgs(TRUE))
> x = as.numeric(args[1])
> print(x)
>
> res <- conditional1(x)
> cat("result= ",res,"\n")
>
> conditional1 <- function(x){
>        result <- 0
>        if (x > 0) {
>                result <- 1
>        } else if (x < 0) {
>                result <- -1
>        }
>        return(result)
> }
>
>
> The output:
>>R --no-save --slave --args 1 < test1.R
> [1] 1
> result=  1
>>R --no-save --slave --args -1 < test1.R
> [1] -1
> result=  -1
>>] R --no-save --slave --args 0 < test1.R
> [1] 0
> result=  -1
>
>
> The problem:
> For arguments 1 and -1 it works as intended. For 0 (zero) it does not. If the 0 value is passed into the function named "conditional1"  I would expect both if-statements to evaluate to false and 0 being return. From what I can tell (0 < 0) evaluates to true since -1 is returned. Hmmmmm...
> What is going on? What am I doing wrong? Why is this happening? I am baffled!
> Any help would be appreciated.
> Thanks
> Mike
>
>
>
>
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>
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