I have a few thousand rows of stock market data - one row for each
day. I'm using ActiveRecord to perform database operations.
I'm interested in performing a calculation on each row while
incorporating the result of the calculation on the previous row, and
then once the calculation has been performed for all rows, perform a
new calculation that uses the individual calculations of each row.
I figure that I'll start with an array of size 3,000. Then I would
probably want to iterate over it, possibly saving the result of the
operation of each row to a new array but this area is a little foggy.