Evaluating a multivariable function XXXX
On 11-05-07 4:06 AM, Dan Abner wrote:
Hello everyone, I have the following R code for a multivariable function:
fn2<-function(x,y,z){(y+2*z)/(5*y-x*z)}
fn2(-5,-2,3)
[1] 0.8 No problems. === If, however, I call the function using a vector substitution for the arguments, R sees this as 3 separate calls to the function while supplying only the first argument:
in2<-c(-5,-2,3) in2
[1] -5 -2 3
fn2(in2)
Error in fn2(in2) : argument "y" is missing, with no default === How should I call the function using the vector substitution method so that R sees that this is a single call to the function that supplies all 3 of the arguments?
The simplest way is to write a new wrapper function: fn3 <- function(xyz) fn2(xyz[1], xyz[2], xyz[3]) You can also do it with do.call: do.call(fn2, as.list(in2)) Duncan Murdoch