Converting a function to one



Hi List,

I have an expression containing many calls to the same function say 

f(someargs)+f(someotherargs)/f(somestuff)
 
and I want to know what is the fastest way to change all of the occurrences of this function to the number 1.  I want/need to do this in my program to eliminate pwdelta(someargs)'s inside of an integral and so that is the reason for my question.  I have been doing it a silly way by creating a new function and using opsubst(g=pwdelta, expr) where g is defined g(x):=1.  Is that the best way?  It is pretty fast, but is there a better way?  One problem I get is that I have to do an ev(opsubst(g=pwdelta, expr), nouns) to get Maxima to change the g's to a 1 and I have been observing in the list that ev() is a problem function.
 
Thanks for any help,

Rich