when I add print (BV[0]), i get:
IndexError: array index out of range

when I add print (BV), i get:
<backtrader.functions.If object at 0x7f1565ab8310>

• an object somewhere in memory?

class tester(bt.Strategy):

    def __init__(self):

        h = self.data.high
        l= self.data.low
        c = self.data.close

        BBBV = bt.And(h(-3) > h(-2), h(-2) > h(-1)) # 3 highs down in row
        BBV = bt.If(BBBV, h(-1), float('Inf')) # returns h(-1) or Inf
        BV = bt.If(BBV < float('Inf'), BBV, float('Inf'))  # returns only non-Inf BBV? or does this do something else?
        self.buy = c(0) > BV

BV = value created with bt.If as a line in __init__
every value in this line should be < float('Inf')

buy = if c(0) > BV

scenario 1:
data = 5min ohlc
BV occurs at 9:05 am
c(0) > BV occurs at 9:10 am
buy signal occurs

scenario 2:
data = 5min ohlc
BV occurs at 9:05 am
c(0) > BV occurs at 9:35 am
(all prices between 9:05 and 9:35 < BV)
buy signal does NOT occur

If c(0) > BV occurs in the 5min bar that comes immediately after BV then buy signal happens.
but if c(0) > BV occurs in a 5min bar not immediately after BV the buy signal does not happen.

Shouldn't c(0) be compared to the last value created in the BV line, no matter how long ago it
was created?
Why does scenario 2 happen?
How to enable a buy signal in scenario 2?

Thanks.

Test_A

    def __init__(self):

        self.data.high
        self.data.low
        self.data.close


    def next(self):

        h = self.data.high
        l = self.data.low
        c = self.data.close
        buy_signal = self.data.buy_signal = c[0] > h[-1] and (h[-3] > h[-2] > h[-1])

        if buy_signal:
             self.buy()

        elif self.position:
            if c[0] < min(l[-3], l[-2], l[-1]):
                self.close()

Test_B

    def __init__(self):

        self.data.high
        self.data.low
        self.data.close


    def next(self):

        h = self.data.high
        l = self.data.low
        c = self.data.close

        # is the result of this logic below same as Test_A? if not, 
        # how to implement Test_A logic w/ bt.If/bt.And?
        pattern = self.data.pattern =  bt.And(h(-3) > h(-2), h(-2) > h(-1))
        A = self.data.A = bt.If(pattern, h(-1), float('Inf'))
        B = self.data.B = bt.If(A < float('Inf'), A(-1), float('Inf'))
        buy_signal = self.data.buy_signal = bt.If(B < float('Inf'), c(0) > B(-1), False)

        if buy_signal[0]:  # error here: "IndexError: array index out of range"
             self.buy()

        elif self.position:
            if c[0] < min(l[-3], l[-2], l[-1]):
                self.close()

Test_B is my attempt to implement the same strategy as Test_A with the use of bt.If and bt.And.

I get this error: "IndexError: array index out of range "

Where are the flaws in the logic?

How would I compose Test_A using bt.If and bt.And?

Thanks.

@ab_trader said in IndexError: array index out of range:

def __init__(self):

Can bt.And be used like this?:

condition = bt.And(A < float('Inf'), A > b(-1), A < c(-2), A > d(-3))

would all the A's after the A < float('Int') be smaller than infinity?

Thanks.

NameError: name 'buy_signal' is not defined

Get this error: NameError: name 'buy_signal' is not defined
even though I have defined 'buy_signal' in def __init__(self):

	def __init__(self):
		buy_signal = bt.If(A < float('Inf'), c(0) > B, False)
		sell_signal = bt.If(C < float('Inf'), c(0) < D, False)

	def next(self):
		if buy_signal[0]:
			self.buy()
		elif sell_signal[0] and self.position > 0:
			self.close()

Thanks.

Is bt.And only allowed to have 2 elements for the condition description as well?
Would I be able to build or chain together a higher number of elements with and?
for example:

condition = bt.And(d(-3) > e(-2), e(-2) > f(-1)) \
            and bt.And(i(-5) > g(-4), g(-4) > d(-3))

Thanks.

@ab_trader said in IndexError: array index out of range:

infline = bt.LineNum(float('Inf'))

thanks, but the change to infline still produces the same error:
TypeError: __bool__ should return bool, returned LineOwnOperation

x is different from y, because it returns d(-1) instead of e(-1),
unless I am stating the bt.If incorrectly.

@ab_trader

Thank you, I have replaced the [] with () and the out of range error has gone, but now I have another error:

    def __init__(self):

        x = bt.If(d(-3) > e(-2) > f(-1), d(-1), float('Inf'))  # new error here

 # error message: TypeError: __bool__ should return bool, returned LineOwnOperation     

Thanks again.

Why is this error message coming up with this line?

# error message:
    return self.array[self.idx + ago]
IndexError: array index out of range   

    def __init__(self):

        x = bt.If(d[-3] > e[-2] > f[-1], d[-1], float('Inf'))
        y = bt.If(d[-3] > e[-2] > f[-1], e[-1], float('Inf'))
        z = bt.If(y < float('Inf'), y[-1], float('Inf'))  # error message line

Thanks.