Hi, I'm interested in finding out just how the forcePositive background correction is implemented. The lumiB help file description of the offset (minus minimum value plus one) is a little vague for me to grasp. Could someone please point me to a reference or code which I can use to understand how minus minimum value plus one is implemented? Thanks for the help, Scott Scott A. Ochsner, PhD One Baylor Plaza BCM130, Houston, TX 77030 Voice: (713) 798-6227 Fax: (713) 790-1275