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Wednesday, May 29, 2024

How to add FILTERS to a STRATEGY SCRIPT 🤖 AutoView Guide

 all right traders welcome back to another pinescript lesson this is the second last blog post i have planned in my auto view series so if you haven't watched the previous videos make sure to go back and watch them because this lesson will build on the previous lesson where we built out the strategy script that you see on my screen right here in today's lesson we're going to add a bunch of filters to this script so we're going to add an ema filter an atr filter a time of day filter and a date filter we're also going to implement our gtd code for our limit orders our expiry code that calculates the expiry date for the limit orders we send to oanda so i hope you're excited to get started adding filters to our scripts is quite easy all we need to do is create a series of boolean true or false values and add them to our setup detection the hardest thing about implementing filters into your scripts is you need trading experience and creativity so you need to understand how the markets work so you know what an effective filter might be and then you need to have the creativity to build that filter and implement all the parameters you think might be necessary so today should be an interesting lesson for those of you who have never done this before and for those of you who have done this before maybe this lesson will inspire some new ideas for your own scripts so let's get started here i am with the script from the previous lesson nothing has been changed since that lesson yet uh before we continue i just want to address these warnings we're getting down here in the editor in case you're not sure what's going on here the first one here is that the tradingview team have implemented new functions called color.new and color.rgb these are the functions we should be using to specify the transparency of our plots because the trans parameter argument function argument will be deprecated soon which means basically made redundant and is no longer encouraged to be used in your scripts so you can ignore these warnings for now it doesn't really matter but this is a new habit i'm personally going to have to get into with my scripts is using these functions to specify the transparency of my plots not sure why they chose to do this because i thought the transparency argument was quite convenient to use but i'm sure they have their reasons and then the last two warnings here say the function two whole should be called on each calculation for consistency it is recommended to extract the call from this scope so if we go down to line 84 that is because we are calling this function two-hole within an if block so everything that occurs within this if statement will only occur will only execute if this boolean is true and that is not going to be the case on every bar on our chart which means that whatever this function does will not be consistent if it depends on bar data in order to calculate whatever it outputs in this particular case this two-hole function is only converting pips into whole numbers it doesn't depend on any actively changing data on our chart so it doesn't matter that this function is being called within this if statement if however we were calculating something within this if statement using a indicator value so for example if we needed the atr distance and we did something like this this would produce incorrect calculations because the atr function needs to be executed on every single bar on our chart in order to accurately calculate its value over the past 14 bars and so what we would need to do in this case if we were using an indicator function or any function even a custom function that depends on price data we'd need to extract the call from the scope that's what that warning means so what you would need to do is create a new variable here and then paste that over the top of this indicator call this could be anything this could be an rsi or a macd anything that or moving average anything that requires previous data you would need to extract that call from the scope so i just wanted to go over that really quickly before we move on because i feel like i'm doing you guys a disservice if i don't explain that information so the first thing i want to do today is add the gtd functionality to our script so the expiry for our limit orders we've already got the input for this our days to leave limit order so if i scroll down to just before we begin calculating our stops and targets this is where i want to calculate the expiry date for my limit order so i'm going to call this set up our gtd good till day or date border info so the first thing we need to do is get the time in milliseconds for the date we want our order to expire on so for that i'm going to create a new variable called gtd time and this is going to be set to the current bar's time plus and then we need to calculate how many milliseconds from now from the current bars time would constitute x amount of days from wherever we are so this is set to 2 by default we need to calculate two days worth of milliseconds and add that onto the current bar's time to get the expiry time and then once we have that time in milliseconds we can use a bunch of pine script inbuilt functions to convert that into a date so we could just google how many milliseconds are in a day and times that number by two but a more intuitive way might be to break down this math so we need to get how many days we want our limit order to be on the broker or exchange for we need to multiply that number by how many minutes are in a day 1440 then we need to multiply that number by how many uh seconds are in a minute which is 60 and then to convert that number into milliseconds we need to multiply that by 1000 so this will give us two days worth of milliseconds and add that onto the current bar's time in milliseconds and if you're not sure what we're working with basically pine script when working with time deals in unix format which is the number of milliseconds that have elapsed since midnight of the first of january 1970. so that's just a standard programming practice to use this unix format and this number gives us 86 million four hundred thousand milliseconds per day so that's the hard work now all we need to do is convert all this information into a date and then convert the date into a string to add to our auto view command so first we need gtd year then we need gtd month then we need gtd day of the month and then finally we need our gtd string which will convert all this data into a into text so first up gtd year we just use the inbuilt function year and we pass our gtd time into that and that will retrieve the year from this unix timestamp same with the month gtd time and same with the day but for here we need to use day of month gtd i'll just keep doing that gtd time it's hard to type around my microphone sometimes i need to uh i need to work on that so now we have all the information we need to calculate our date it's time to convert that into a string so for this we need to specify our order view parameter out the syntax for specifying this command which is dt or date slash time and then we need to add and convert these numbers to strings so that the script will compile first we need to add the format for this is the year first and then we need to add a hyphen and then two string again and then the second parameter is the month and again another hyphen and then the final parameter is our gtd day of month so this would give us the current time of today plus two days worth of milliseconds so whatever time it is right now this string here will be set to the date of two days from now and that's it really all we need to do now is add this string to our order view parameter list here and you can add it in anywhere i personally added on at the very end so we just add a new string here and then for this we have already put in our date time parameter here syntax command and now we can just add our gtd string variable here but we need to check if the user is actually using a limit order before we just pass a two day expiry because they might not have this turned on and they don't want this number to be used at all so the way we check that is we use a conditional statement and we want to check is the gtd order not equal to zero so the user has set the days to leave limit order to something other than zero and have they turned on the limit order checkbox here so if the user turns this off and the script detects a setup on the current bar then a market order will be sent to oanda to buy or sell at market with our stops and targets and we'll pay the spread if the user turns this on but sets this to zero then the script will send a limit order command to oanda at the closing price of our setup and our stops and targets the same as the market order except that the limit order will stay on our broker indefinitely for whatever the maximum time is and then finally if the user changes this number to something other than zero so if you set this to zero this disables the expiry date if you set it to a positive number this is how many days we want our limit order to stay active so now the final thing is to check if this condition is true then we want to pass our gtd string to the end of our alert syntax otherwise we just want to pass nothing just a blank string then we need to add a comma on the end here we can copy this line of code and paste it to our short trade command as well since this information applies to both long and short trades so now we can save the script and we have a error uh let me check what that is 93 plus i forgot to get rid of this comma here at the end of ftp and i probably did the same there yep so now the script should compile because remember all of these parameters belong to all of these arguments for this alert message parameter is just one long string broken up by concatenations or these plus signs and so we need to add the comma at the very end of all of these lines which is why i got an error just then so the script is now compiling everything's working fine we have added expiries to our limit orders so if we come up to the settings menu if we set this up and i leave this as it is and i come up and set an alert select the script and select alert function calls only if i were to click create now then next time a setup is detected the script will send a limit order with a two-day expiry to oanda to enter into the position at a good price ignoring the spread so obviously this is not trading advice i'm not encouraging you to go and trade this script it's not that profitable anyway uh because it is a daily chart strategy and it only works on forex and it only works on a handful of forex pairs it's not an extremely profitable script but it does work on some pairs as you can see here the 57 win rate with a one to one risk reward is profitable and we can bump this up as high as 1.4 and still have a 50 win rate so it is a profitable script but 184 trades from the year what 2000 or something is not a lot of trades so even though it's profitable i wouldn't suggest trading this script or if you do trade this script it should really be part of a wider portfolio of multiple strategies but i'm not allowed to give trading advice because i don't know your risk preferences your risk tolerance i don't know your financial situation your trading experience all of that so none of this is trading advice this is all for example purposes but in saying that i am using this script myself in my own trading and so far it has been working just fine one thing to note is you might want to change the day days to leave limit order to three so that if you get a signal on a friday and there's a long weekend or something you can still get filled on the monday or tuesday or even four four days four or five days on a daily chart strategy is not an unreasonable amount of time to leave a limit order on your chart to get filled by price action if we were trading a 15-minute chart or something then yeah maybe three days would be far too long remember the purpose of having this gtd order is to prevent the script from leaving a position let's say for example the script detected a short trade here but price action just fell from here all the way down to our target and never filled our limit order we don't want the order to stay on our chart any longer than necessary to give the limit order time to be filled because otherwise if this scenario were to unfold we could end up getting filled after the trade's already played out hit our take profit and then it might come up and stop us out and then we just took a loss on a trade that does not meet our trading strategies rules because it's already played out and we've missed it so that's the purpose of having an expiry on limit orders we use limit orders to mitigate the issue of spread but then we use the expiry to mitigate the issue of leaving our limit orders on for too long and then finally before i move on to the filter section of today's lesson it's worth noting that you can change this to something like hours let's say you wanted to leave a limit order that only remains active for one hour you could simply change this to sixty thousand and this would add sixty thousand milliseconds or one hour to the current time and one hour from the time that your order is sent to oanda it will expire so this particular script is designed and optimized to be traded on the daily chart so this approach doesn't really make sense if you were using autoview to automate a script that trades a lower time frame then that is how you would add a limit order with an expiry that only lasts a few minutes or a few hours but to keep today's lesson short we'll leave that there and we'll move on to the next section of this lesson which is adding a couple of filters to our script to hopefully optimize our trading setup accuracy or quality so let's come up to the top here because we need to add a bunch of new user inputs i'm going to keep these new inputs separate from the existing ones just to make the changes we're making to the script a little easier to read so i'm going to create a new comment here called filter settings and the first setting we're going to create is an atr filter now these are filters i already use in my existing scripts so i'm just going to copy and paste the inputs for these particular filters just to save time because you don't need to sit here and watch me type out 15 lines of inputs you should already know by now how inputs work if you've watched any of my previous videos so the first inputs we're working with here are our atr minimum filter size and atr maximum filter size and these are just float inputs with a default value for the minimum of 0.0 and for the maximum of 3.0 so the minimum atr filter means that the current bar the size of the current bar from its high to as low must be at least this many times the atr so by default it's essentially disabled because zero times anything is zero and so any bar size will meet this condition by default the second filter here though is set to three so if the bar size is three times the value of the atr then the setup will be ignored because that bar is far too large to enter on and this stops the script from entering on like flash crash candles like this one if we were to enter long on this bar with a stop loss below this low and a target up here i mean we could be in this trade literally for years and so that's the purpose of having an atr filter in our script so if i save this script now we should have two new inputs up here here they are down the bottom in their own filter section and now let's add this filter to the script so first we need to check atr filter and we need to check the atr minimum filter and the atr maximum filter so for this we need to calculate the candle size in pips so we just subtract the low from the high and that will give us the size and pips of all the bars on our chart and we need to compare this is this number greater than or equal to our atr min filter size multiplied by the current atr value if this is true then the candle size exceeds our minimum filter size and this is a valid setup or if atr min filter size is set to 0.0 then the user has disabled this filter and this min filter boolean will also return true and if either of these conditions are not met it will return false and the setup will not be taken we need to do the same for our max so the high minus the low needs to be less than or equal to our atr max filter size multiplied by the current atr or the user must have set our atr max filter size to 0.0 now we simply add these two filter checks to the setup detection code but before we do that because we are adding multiple filters to this script i'm going to preemptively set up a few variables where we can combine all of our filters for long and short trades so here i'll just say merge filters and we'll have our long filters and our short filters but first let's merge our two atr filters so atr filter is going to be atr min filter and atr max filter so we need both of our filters to pass their checks in order for this to be true and we can paste that into our long and short filters now if we come down to our valid hammer and valid star setups and add on the end here a hammer candle is a long setup so we need to check our long filters and the opposite for our short trades we want to check our short filters now we can save the script make sure everything compiles which it should and there we go so let's play around with these settings make sure they work let's set the minimum atr filter to three that should remove all of the setups on our chart because an atr or a candle size greater than three times the atr is very rare on the daily chart so that's working let's change our maximum atr filter to one and see what that does there we go that changes the setups that are detected to only very small candles and you can see how that affects your win rate and your trade quantity and all of that and that's the point of these filters so that we can play around with them and see how they affect our win rate okay so that's our atr filter let's move on to the next filter i want to add which is an ema filter so for this i'm going to comment this as ema filter and we need to get an ema filter length and again i'll just copy and paste this over to save time this input is just getting an integer input by default it's set to zero and that means that this filter is disabled you could add a checkbox like this for these filters but i find that just setting them to zero to disable them reduces interface clutter so that's why i take this approach so this will be our ema length for this filter so next up let's check ema filter so for this we need to get an ema value and first we need to check is ema filter length set to zero if so then we don't want to do anything we want to set ema to na or null otherwise we want to get the current ema based on the closing price and pass in our ema filter length as the ema period length for calculating this moving average so now we have our ema variable or value we can check our ema long and short filters and for this it's going to be extremely simple while price is trading above the ema we will only look for long trades and when price trades below the ema we will only look for short trades or star candles so for that we need to create two new variables ema long filter so if our ema filter length is set to zero then our ema filter is disabled and ema long filter will return true so we want all of our filters to return true in order to have a valid setup so this will return true if the user has turned ema filter off or left it disabled or if they haven't set email length to zero we want to check if the current closing price is greater than the ema value and the ema value is not n a so remember when dealing with indicator values on our charts it's important to check that the ema has been calculated so 50 ema for example on our chart needs 50 bars to plot onto this chart before it can start calculating its values and so if we don't add this check in here to make sure that the ema has a value that can mess with how the script detects our filters and if you remember from the previous lesson i went over that when we added our atr na check so that's our ema long filter check next we need our ema short filter which is going to be the same sort of thing we need to check has the user left ema filter off or is the closing price of the current bar less than the current ema value and the ema value is not n a just to make sure this is working we can add a visual check here we can add a plot that checks is the ema filter length equal to zero if so we want to plot nothing otherwise we want to plot our ema value and then we can change the color based on whether price is above the ema so the if price is above the ema we can set the color to green otherwise we can set it to red and then we can title this ema filter all right so now if i save the script we should have an ema plotting onto our chart when we specify an ema length in the settings menu so there we go script is loaded let's change our ema length to let's do 50 and now we have a 50 ema plotting onto the chart changing color based on whether price is above or below it the last thing we need to do is add this same check to our setup detection and the purpose of this i don't know if it will increase the accuracy of the script or not but the purpose of this is to stop taking short trades when price is trading to the upside all of these filters are just for example purposes so it's possible that some of these filters we add may decrease the accuracy of the script but that's okay this is all for example purposes and that's why i'm leaving the filters off by default so now if we come down to our long filters we can add and ema long filter and add and ema short filter to our short filters save the script and then we can check to see if the script will still take the short trade if we put the ema filter onto 50 5 0 okay and that trade goes away and the accuracy of the script has actually increased a little bit i think our trade quantity has decreased but the win rate has gone up just slightly 57 percent so that's interesting something to play around with uh 10 ema 20 ema 20 ema actually produces a 61 win rate over as still a decent sample size being that this is a daily chart that's pretty cool so there's a successful ema filter added to the chart and just because i like to keep my scripts tidy i'm going to move this plot down to the end here i'll just paste it under draw trade data and come back up and we'll add our next filter which is going to be a date filter so date filter i'll copy these inputs over yet again so these inputs are getting a input.time data type which is a timestamp and you can see here that we've passed two default time stamps between 1st of january 2000 and 1st of january 2099. and so by default the script will only take trades between these two dates you could change this if you wanted to something like 1000 to include all of price history on any market you load the script onto and then if you want to fine tune your start and end date you can do that in the settings menu so let's come down to our ema filter and add on our date filter underneath there and for this all we need to do is add a new boolean called date filter and this one is the easiest filter of all all we need to do is check if the current bar's time its unix timestamp falls between our start time and our end time so is the current bar's millisecond unix timestamp greater than or equal to our start time timestamp and is the time of the current bar less than or equal to our end time timestamp so now if i copy this boolean onto the end of our long and short filters we have now added a date filter to our script and so if i come up to the settings menu and we change this to 2000 and let's go 20 click ok if i zoom out you can see that the script is no longer taking any trades that fall between 1st of january 2020 and we can see how these strategy performed over certain time periods so for example we could see how it performed during the 2008 financial crisis so between 2007 2009 uh it still had a decent win rate 51 1.4 profit factor so that's the purpose of a date filter it's useful for back testing your script and just seeing how it performed during certain periods of time and then there's one more filter i want to add to the script which is a time filter now this particular filter is not particularly relevant to the script because as i mentioned earlier this is intended to be a daily chart trading strategy so having a time filter is kind of pointless for the script but i figured while we're here i might as well show you guys how to do this because it's almost as easy as making the date filter so we might as well do it while we're here just so that you guys can go and play around with this in your own scripts in your own time so i'm going to copy these filters as well to save time and we're getting two variables here from the user the first is our time session this is the time session to ignore trades and it uses a type of input.session and the second input is just a boolean checkbox that determines whether or not we actually use the time session filter because there is no way to set this to zero like we can with the ema filter or the atr filter so now we have our session we want to check if the current bar's time falls within this session and if it does we don't want to take any trades so to do that let's come down to our date filter and add in our check time filter code so for this i like to create a custom function called is in session and this custom function is only going to take one input parameter or argument and i'm just going to call this one sess short for session and then we need to declare or define the function and what it does using the equals and then right arrow operator and this function is going to check if the time of our time frame dot period in this current session is not n a so there's a bit going on here let me just break this down so the first thing we're doing is getting the time of the current bar for the specified resolution and session so we've passed in our session which by default is between 6 am and 9 15 am which happens to be when the spread in my place in the world is terrible i don't like trading between 6 am and quarter past nine because my spread is as high as 10 times what it normally is that is why i'm using that session as the default and so we're checking is the current bars time frame within this session that we have specified if it isn't then this time function will return n a and our n a function check will return true and so this block of code here will be true if the current bar's time does not fall within the session we've specified so we're checking if this is equal to false that means that the current bar is within our specified session and is in session will return true otherwise if it's not within that time period it will return false and now we have our time filter so before we use the time filter we need to check i'm going to create a new boolean variable here called time filter and we're going to check is use time filter turned on and are we not in the session that we want to be in or has the user turned off use time filter so if use time filter is not on time filter will return true however if use time filter is turned on and the current bar is not within the session that we've specified and of course we need to pass our session into this function which is this variable here time session this user input paste that into our is in session function call now if i save the script this time filter will return true if the user has turned on the time filter and the bar is not within the session they've specified so let me add on to the end of our filters and time filter and now if i save the script if we come up to the settings menu we now have this new filter at the end of the list so if i turn this on then the script will not take trades within this time period so that's it the script is pretty much completed now just before we wrap things up i will add a quick visual indication for our filters so in this case i want to change the background color of our chart to red if any of our filters are not met so for this i'm going to use the bg color function and i'm going to set the color to and then i want to check is use time filter turned on and are we in the session that we have specified or do we not meet the requirements for our date filter or do we not meet the requirements for our atr filter the only thing i'm not going to check here is our ema filter because if prices above the ema we're looking for longs and if it's below looking for shorts if any of these filters are not met then we're not looking for any trades so i want to set the background color of my chart to red when any of these filters are not met or not satisfied so that we know what the script is doing so i add my conditional check here if any of these are true then we want to set the background color to red otherwise we want to set it to nothing leave it as it is i want to set the transparency to 70 percent and i'll title this filter color and close that off and now if i say the script hopefully that should compile without any problems and our script is now finally completed so let's play around with some of these filters first of all let's check the time filter let me go down to a 15 minute chart and turn on our time session filter now you can see that the background of the chart goes red between 6 a.m and 9 a.m and you can see here that this bar here is obviously greater than three times the atr and that's why the background color turned red for that bar so if this had been a valid trading pattern we would not have entered it because it is invalidated by our atr filter the script is completed this will not be profitable it was highly unlikely to be profitable on lower time frames maybe the higher time frames like 4 hour and above i'm barely about break even but the daily chart is where this particular strategy is the strongest because of the concept we're trading here hammer and shooting star candles are far more reliable on the higher time frames than the lower time frames where there's a lot of noise so that will about do it for today's video hope you found that interesting a link to the source code will be below this video in the video description the next lesson in this series is going to show you how to set up a virtual server private server through something like amazon web services is probably what i'll use so that you can run auto view in your browser 24 7 without needing to leave your computer on if that's not an option for you and then i'll wrap up the series there any future lessons i create on this subject will be going up in the pine script mastery course and i actually want to move on to different topics on this youtube channel in the months to come i'll still be doing pine script videos but just less frequently i'm planning to move over to more general trading related videos make sure to hit the subscribe button i'll be back real soon with a new lesson but if you can't wait for that there's plenty of lessons over at panscriptmastery.com including my free basics course and the panscript mastery course which now has over 100 lessons and 14 hours of content covering pinescript in great detail and of course if you want to steal all of my source code for every script i've ever written over the past four years there is my indicators and strategies course which contains the source code and detailed lessons several hours of video lessons breaking down the source code to all of my most popular scripts take care thanks for watching to the end and i will be back real soon good luck with your trading and thanks for being a part of this community

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