Hi (vagy Szia), GetQuotesEx has 5 important params: Ticker... Periodicity tells what timeframe the DB uses. Size=how many quotes the db can have at maximum (size of the array of quotes). LastValid is the index of the last quote in the DB. pQuotes is the pointer to the first quote.
Think of the DB as an array of quotes. You fill in as much quotes as you can or as much as the db can accomodate (preferences settings!). A chart/exploration/scan/etc. will use as much quotes as it need or as much as available. I hope it helped. Even if you want to use C to code your plugin, look at my .Net SDK. The new version (.Net SDK 2.0 yet in Beta 2) supports data and optimization APIs. The data source API samples may give some hints. http://sites.google.com/site/dotnetsdkforab/ Regards, Jozsef --- In amibroker@yahoogroups.com, "gy.lukacs" <lu...@...> wrote: > > Hi > > I'm about to write a data plugin and having problems understanding the > timeframe covered by such a plugin. > > Let's assume I have a DB of 1000 ticks on a DB server and I have memory to > show only 50 on the client (AmiBroker) side. I want the client to be able to > access historical and realtime data. How can the data plugin get which > timeframe to use to fill the buffer given by GetQuotesEx? Which 50 ticks to > get? I'm thinking about something like this: > > - if the user scrolls left he will get older data > - if the user scrolls right he will get more recent data > - if the user sees the latest data he will get realtime data > > Is it possible somehow? Is this a common scenario? What about backtesting, > walk forward testing and other optimizations, can I use such strategy with > them or should I try to store every relevant tick in the client side cache? > With time compression I can save memory, I know, I just want to be nice to > user memory. > > Thanks, > lukit >
