This would still be faster than recalculating the values ... And if you create the report definition for all 4 surfaces and checked the box per zone, the function will return the 4 values separately ... nAnyway, your function seems right but has two minor corrections which will not make much difference .. but let's trynnAdd this before calculating the average pressurentotal_area = PRF_GRSUM1(total_area);nand correct this, use the magnitude instead of vavgndyn_p = 0.5*dens*pow(vmag,2);nn