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plotting pivot points or lines



  • I'm working on a strategy which requires pivot points. So far, I got it to go back 50 candles and basically compare that candle (low[-50]) with the last 100 candles to see if it's the lowest. This gives the low pivot points (they are offset by 50 though, because you can't compare to future candles while running live). Anyway, i'm trying to figure out how to plot it because I don't know how to plot a custom variable. I would like to plot it with an offset of 50 if possible. This is what I have so far for the pivot points:

    Init()

    self.base = bt.LineNum(float('1.0'))
            self.counter = 0
    

    next()

    self.counter = self.counter + 1
    
            self.isLower = True
    
            for i in range(-2 * self.p.pivotSize, -1):
                if self.counter > self.p.pivotSize:
                    if self.datalow[-1 * self.p.pivotSize] <= self.datalow[i]:
                        self.isLower = True
                    else:
                        self.isLower = False
                        break
    
            if self.isLower == True:
                self.base[0] = self.datalow[-1 * self.p.pivotSize]
                print("new base has been found!" + str(self.base[0]))
    

    The counter is just to make sure there are 50 candles to look back to, so on the first 49 candles or w/e you don't get out of range error. I'm pretty sure this works but just can't figure out how to plot. The docs are really oddly worded and they tell you how to plot indicators, so do I have to make this into an indicator or something? It would be nice just to be able to program everything in the strategy.



  • @Wayne-Filkins It would be nice if they just had a simple line / dot plot function, so I could just be like plot(self.base, line) or plot(self.base, dot) or something and it just plots it. I'm not that great with python or learning frameworks like this so all the extra files like indicator files and "observer" files just confuse me.



  • LinePlotterIndicator,
    Docs - Indicators - Usage



  • Try this as well

    You could probably execute all of your code in one line and have it available to plot. You need to learn to make the jump to vector thinking and not be constrained by loops.



  • @ab_trader That sounds like what i'm looking for, but when I put it in init() or next() it doesn't work. Am I supposed to put it somewhere else?

    I just put

    LinePlotterIndicator(self.base, name='base')
    

    and it says it's not defined.



  • @ab_trader okay I put bt. before it and now I got "IndexError: array assignment index out of range"



  • @run-out Could you please explain or link a Youtube video or something where I can learn what you're talking about?



  • @run-out Oh you mean likle using Min() instead of how I did it, yeah I knew as I was doing it that there were probably way better ways. I'm just not that good at this stuff. I have learned Python like 5 times throughout my life and I just forget everything, it's really odd. Now i'm in my 30's and just doing w/e to get by, you know just trying to get it functional. My trading strategy is on the 4h chart so it doesn't have to be super fast or anything. I'll try to write it better, but I still can't get the damn thing to plot :(



  • @run-out actually I think I have to use a loop because i'm not trying to find out if it's the lowest, just the lowest in a range. Not sure how else I can do that.



  • @ab_trader Holy shit I think I got it working. I had to declare it as a line instead of using bt.LineNum(float('1.0')) because now it's plotting them. Now I just have to figure out how to offset it by 50 so the dots are in the right place. Idk if it's working right but there are dots on the chart so finally making some progress.



  • Looks like you are developing fractal indicator, which is already in the bt package, check out Docs - Indicator - References



  • @ab_trader What i'm doing gets far more complex, that's why I need to really learn how to do all this stuff. I need to get the pivot points first and use them for 2 parts of my strategy. Then I have several other parts. It works but it's not like any strategy which exists it's too complex and customized. I'm using it live and it's working, but I need to spend hours finding the right stocks and the risk management gets complex too so I need to automate it so I don't have to spend all day every day finding stocks, monitoring, and making trades, and I can really get the most profits out of it. Also sometimes I miss opportunities because i'm trying to watch hundreds of stocks all the time so I lose some profits to that.

    If anyone is really good with backtrader and wants to help with this they can use it too. It's super profitable but really needs to be automated. It cannot be shared with anyone else though. No one knows about this and it took me about 2 years to get it just right.



  • @ab_trader I made a fractals indicator before on TradingView. It is kind of like that because that basically finds pivot points and connects them via lines, but I also need to reference the pivot dots for other reasons so if I used that one i'd have to modify it and I have no clue how indicators even work on here yet :(



  • Go thru the beginning of the docs and Quickstart, it will help you to understand bt internals. Otherwise you would be spending time on the things already made.

    I am more than sure that fractal indicator returns true or false, that can be used for reference.



  • @ab_trader Yeah i'll try the quickstart. These docs are the hardest docs I have ever tried to read. I don't know if it's the vocabulary the guy uses or what just so much stuff doesn't register in my brain. Every time I look something up it makes no sense to me. Like with plotting, there's info about plotting all over the docs. The one guy showed me LinePlotterIndicator() and that isn't even in the plotting section of the docs. I'm also not that great with python so I guess it'll just take me a while to get the hang of it.



  • @ab_trader If I can use the fractal indicator to reference the true/false for any candle, like fractal[-14] to find out if 14 candles back was a high or low, then it will work, because I have to be able to get the high/low value from the fractal, not just knowing whether or not it is. I'll mess around with it, definitely looks cleaner than my method lol.


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