R: Passing function arguments to override defaults of inner functions -

in r, this: have function f1, has argument default value; k=3.

f1 = function(x,k=3){     u=x^2+k     u }

i later define second function, f2 calls f1.

f2 = function(z,s){     s*f1(z) }

what's cleanest way allow users of f2 override default value of k in inner function f1? 1 trivial solution redefine f2 as:

f2 = function(z,s,k){     s*f1(z,k) }

however, feel might cumbersome if i'm dealing large heirarchy of functions. suggestions? thanks.

the easiest way deal using ... argument. allows pass number of additional arguments other functions:

f1 = function(x,k=3){     u=x^2+k     u }  f2 = function(z,s, ...){     s*f1(z, ...) }

you'll see commonly used in functions call others many optional arguments, example plot.

Brazell