I'm evaluating various trading platforms. An important feature I need is the ability to draw trendlines on charts. I did some forum searching and couldn't figure out how this might be done. Perhaps someone could point me to a link? Also, is there a limit on how many trendlines can be drawn on a chart? Thanks.

Great. Is it possible to draw trendlines programmatically?

I'm working on a 3rd party add-on for other trading platforms running a common DLL logic codebase and we've had a user request that the add-on run on Metastock. Hence, my questions... Ok. I suppose a trendline value for each bar could be calculated within a DLL and passed back to be plotted. But I'm interested in plotting dozens or a couple hundred trendlines at certain times which would mean a lot of values plotted. Possible?

Ok. I understand how I could use functions like these to plot trendlines. But calculations determining trendline start and end points are in a DLL. The data for the trend lines is passed to the trading platform(s) in a file. Does Metastock provide some means for reading csv files and parsing the data in csv files? Thanks in advance for this assistance

Thanks wabbit, What you've described makes sense. I just have a few questions about how this might work. 1 I pass necessary data (date/time and OHLC) to the DLL. 2 DLL does all necessary calculations of trend line values bar by bar. (I understand the start and end points issue.) 3 I don't need to pass this data back to MS through a file. I can use a data array. So far so good. But you also say that I can only plot one trendline per external function call. If I had a scheme for encoding the values of multiple trendlines within that array, is there any way I could plot multiple trendline values? Thanks.

Hi asp I thought I'd reply to your post since I have built a dll for trendlines. Wabbit is right in that only one trendline can be passed to Metastock from the dll at a time. The problem is that the MSX DLL has only one data array which is passed to Metastock. Its not possible to modify the data array in the manner I think you want (E.g. create an array of arrays, DataArray[NoOfTrendLines][Time]). However an MSX DLL can have up to 9 input parameters. What you can do is use one of those parameters to tell the DLL which trendline to return. e.g. ExtFml("TrendLineFunc", 1) which return trendline number 1; ExtFml("TrendLineFunc", 2) which returns trendline no.2, etc. Also don't underestimate your point no.2. Formulating objective mathematical rules for trendline construction is a very very tricky process (Its taken me 8 months to get my program to produce replicas of lines which I would draw by freehand) however it is possible. You'll probably find that on the first few gos, your rules will not be specific enough and the program will draw lines in all manner of places but keep going! Regards Craig