Algorithm help on converting infix expression to postfix

I found numerous examples on converting infix expression to postfix expression but my program needs to include some functions like sqrt(x), min/max(x,y), fact(x), abs(x).

abs(‐5) is converted to ‐5 abs
120 – (45+3) is converted to 120 45 3 + ‐
(3^2 + 4^5)*fact(3) is converted to 3 2 ^ 4 5 ^ + 3 fact *
min(3‐(4‐7) , (2+4)/3) is converted to 3 4 7 ‐ ‐ 2 4 + 3 / min

I'm confused about what the precedence of those functions needs to be.

Thanks for your input!

Precedence is not a problem. Read up on Reverse Polish Notation on Wikipedia. Using a small array as a first in, last out stack, it all comes up roses. :D

Take a look at shunting yard algorithm.