Since we have been denied the chance of using interactive debugging for a long time, I have developed a way of spotting bugs through a style of programming which I never used before MetaCrap. It could be refered to as an audit trail for logic: Track the logic by creating intermediate flags which can be logged. I suppose you could call it bread-crumb debugging. Although I spend as a much time adding extra code for this as I do on the core logic it often bears fruit in the long run.
Can you spot the inconsistancy in this dump from an analysis of the M15 zigzag?
Code: Select all , st_bM15ZZ_N1_AboveM15UBB 0
, st_bM15ZzTriNodeUp 1, st_bM15ZzTriNodeDown 0
, st_bM15ZZ_M15UBB_Bias 0, st_bM15ZZ_M15LBB_Bias 0
, st_bM15ZZ_M15StrongUp 0, st_bM15ZZ_M15StrongDown 1
, st_bM15ZZ_M15Up_Bias 0, st_bM15ZZ_M15Down_Bias 0
, st_iM15ZzPrevStepUp 0, st_iM15ZzPrevStepDown 1
, st_iM15ZzBbRangingUp 0, st_iM15ZzBbRangingDown 0
, st_bM15ZzTriNodeBuy 0, st_bM15ZzNoBuyFlag 1
, st_bM15ZzTriNodeSell 0, st_bM15ZzNoSellFlag 0
, st_bM15ZzContraction 0, st_bM15ZzBigContraction 0
, st_bM15ZzBiggerSwingC 0
, st_bM15ZZ_PlBkSwing 0, st_M15ZzSkipCount 0
, st_bM15ZzBreakPrevLow 1, st_bM15ZzBreakPrevHigh 0
, st_M15EntryH4BreakLower 0, st_M15EntryH4BreakHigh 0
, st_bM15ZzExhaustedDown 0, st_bM15ZzExhaustedUp 0
So you are probably wondering how st_bM15ZzTriNodeUp can be true when most flags are indicating a definite downward bias? Yes and you would be right. However, before I tell you how stupid this bug is:
Let he who is without this sin cast the first stone.
It is due to the programmer's curse, that dreaded lazy time saving behaviour known as cut, paste and change.
I try so hard to be consciously careful about this but howmany of our bugs track back to this action?
There are two major contributions to these errors
a) MQL lacked the language constructs: classes, polymorphism, generic templates
b) The buy/sell symmetry
We now have an escape root from the first restriction but the buy and sell symmetry always requires a yin for every yang. There is something we can do to reduce these slip-ups. I have two or three editors open and don't do the paste directly in the original, instead I copy snippets to other editors and finish the changes
outside the original and copy them back in afterwards. This does definitely help me to reduce my self- inflicted faults.
Of course the yang is a generic reverse of the yin so if we could spend some time thinking about that for a new piece of work, but it is too late for this one.
I have just thought about it and the simple solution would be to duplicate the price data stream and just invert the second stream,
so the code is doing buy only trades on say
a) eurusd
b) usdeur
Why didn't I think of that before  |
