Thanks All. In defense of myself, I wasn't using the FOR loop to make an array (I just excluded all the unnecessary stuff from my posting, and seemingly confused everyone even further!) But clearly, I was mixing the semantics of indexing with assignment as Craig pointed out! FOR i=0, 999 do radius(i) = i * 0.25 is the way to go for what I wanted. Thanks for seeing through my morning foggyness. -Eli