Tip on using index variables in DLLs

All three of the popular languages for programming DLLs for the Trader Pro (C, Powerbasic, and Delphi) have both short integers and long integers. Integers are usually used in programming for indexing an array, or in the case of Trader DLLs, to index the bars of the arrays passed by the Trader.

Short integers are limited in size to 32,767. These are going to be OK for use in DLLs that will only be used for daily bars, because few of you will be using more than 32,767 days in your data streams.

However, the DayTrader is a different matter. In minute bars, 32767 is only about 91 days. We can see users loading more minute bars than that. Therefore, it will be a good idea to use long integers for indexes.

If you’ve already used short integers (even some of our examples did that), we’d suggest that you change them to long integers. For example, in Powerbasic, declare them with & instead of %.

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