[R] Elementary sapply question

[Ajay Shah]

I am discovering sapply! :-) Could you please help me with a very
elementary question?

Here is what I know. The following two programs generate the same answer.

--------------------------------+----------------------------------------
       Loops version            |          sapply version
--------------------------------+----------------------------------------
                                |
f <- function(x) {              |       f <- function(x) { 
  return(x*x)                   |         return(x*x)      
}                               |       }                  
values = c(2,4,8)               |       values = c(2,4,8)  
answers=numeric(3)              |       answers = sapply(values, f)
for (i in 1:3) {                |       
  answers[i] = f(values[i])     |
}                               |

and this is cool!

My problem is this. Suppose I have:
     pythagorean <- function(x, y) {
       return(x*x + y*y)
     }

then how do I utilise sapply to replace
     fixed.x = 3
     y.values = c(3,4,5)
     answers=numeric(3)
     for (i in 1:3) {
         answers[i] = pythagorean(fixed.x, y.values[i])
     }

?

I have read the sapply docs, and don't know how to tell him that the
list values that he'll iterate over "fit in" as y.values[i].

-- 
Ajay Shah                                                   Consultant
ajayshah at mayin.org                      Department of Economic Affairs
http://www.mayin.org/ajayshah           Ministry of Finance, New Delhi