The data points need to be accumulated somewhere. A graph is just an indicator. Achart is both an indicator and a buffer which can accumulate data. Depending on what you are doing with the data, a chart can be a good or poor choice of buffers.
My preference is to do my own accumulation so that I have complete control over how much data I have and what is done with it.
Insert into Array is almost never a good choice because, as you have noted, it forces frequent memory re-allocations as the array grows.
The best way is to decide how much data you want to have in memory at any one time. Then Initialize Array to that size (using Nan, zero, or other approriate value) outside the loop. Wire the initialized array to the left terminal of the shift register. Inside the loop use Replace Array Subset to put data into the array. You need to keep track of the index where the data is to be replaced, usually with another shift register.
When the array gets full, write the data to a file and start over.
Lynn
