[R] finding the values to minimize sum of functions

[Linh Tran]

Hi fellow R users,

I am desperately hoping there is an easy way to do this in R.

Say I have three functions:

f(x) = x^2
f(y) = 2y^2
f(z) = 3z^2

constrained such that x+y+z=c (let c=1 for simplicity).

I want to find the values of x,y,z that will minimize f(x) + f(y) + f(z).

I know I can use the optim function when there is only one function, but
don't know how to set it up when there are three.

I would also like to apply this to higher dimensions (i.e. for more than
three functions) if possible.

Thank you for all your help!

--
Kind regards,

Linh Tran, MPH