I use a hierarchy of handle class objects to extract, organize and analyze A/D data. Objects up and down the hierarchy have references to objects above and below them (like a doubly linked list, in c I would say they have pointers to each other but I'm not sure what the correct nomenclature is in Matlab). The code was written on a Mac in R2009b and everything worked fine. I recently upgraded to R2011b, still on a Mac, and suddenly the objects associated with a data set that took a few seconds to delete take more like 10 minutes. Performance monitoring does not indicate that any of my delete methods is taking very long so the problem must be internal to the handle superclass. What has changed that could cause this problem, is there any alternative method to delete a large number of objects quickly and is there any command to just wipe out the whole heap?