Convert MySQL stored function to UDF

I have a simple MySQL stored function. I want it converted into a UDF. The UDF will be installed under 64-bit Linux - CentOS - on an AMD Opteron machine. I want: 1. UDF to achieve the same functionality as stored function. 2. A test harness. 3. The logic will evolve a little bit based on performance of the UDF. Will provide details later. 4. Complete directions for building and installing the UDF Here is a simplified version of the function: DROP FUNCTION IF EXISTS spc; CREATE FUNCTION spc (c double, p double) RETURNS double DETERMINISTIC RETURN ifnull((2 * ((c-p)/(c+p))),0);