hi, for more performance, i am accessing to graph points directly. something like this code:

for(int i=0;i<1024;i++){

this block runs when i receive a 1024-byte packet of data. data should be added to previous data. So i should reserve 1024 sells of memory in first time and 1024 sells in second time(In total: 2048 sells) and ...
how i can reserve memory without deleting previous memory?