[R] else if statement error

[David Winsemius]

On Oct 3, 2009, at 11:54 AM, Chen Gu wrote:

> Hello,
>
> I am doing a simple if else statement in R. But it always comes out  
> error
> such as 'unexpected error'
> There are two variables. ini and b. when ini=1, a=3; when ini>1 and  
> b>2,
> a=5; all other situations, a=6. I don't know where it is wrong.
> Here is my code
>
> ini=3
> b=4
Your basic problem is that you are confusing if and else which are  
program control functions with ifelse which is designed for assignment  
purposes;

 > ini=3
 > b=4
 >   a <-   ifelse( ini==1, 3, ifelse( ini>1 & b>2 , 5, 6))
 >
 > a
[1] 5

>     if (ini==1) {
>  a=3
>     }
>    else if (ini>1 and b>2 ) {
The error is probably being thrown because "and" is not a valid  
conjunction operator in R.
 > 1 and 1
Error: syntax error
 > 1 & 1
[1] TRUE


>   a=5
>    }
>   else {a=6}
>
> e.

David Winsemius, MD
Heritage Laboratories
West Hartford, CT