Hello, When I do gc() I got this return: > gc() used (Mb) gc trigger (Mb) max used (Mb) Ncells 288952 15.5 968217 51.8 381338927 20365.7 Vcells 57781947 440.9 180578758 1377.8 551082632 4204.5 What does actually means Ncells, Vcells, used and gc trigger? Thanks, Rui