Attachments: Coders Corner

Coders Corner

#1
First Post: Edited 11:34pm May 1, 2011 6:35pm | Edited 11:34pm

a_trader
| Joined Jun 2010 | Status: Trader | 113 Posts

This thread serves as a resource to people learning to code.
Any questions about coding are welcome.

This is me giving knowledge back to the community.

This first post will be continuously updated as a table of contents.

//----Tutorials-----

Basic Structure http://www.forexfactory.com/showpost...12&postcount=2
More on basic structure http://www.forexfactory.com/showpost...94&postcount=4
Variables http://www.forexfactory.com/showpost...71&postcount=7

//----Functions you can copy & paste----

Code for 4&5 digit brokers http://www.forexfactory.com/showpost...4&postcount=10
Trading once per signal http://www.forexfactory.com/showpost...0&postcount=11
Counting Orders http://www.forexfactory.com/showpost...9&postcount=12
Closing Trades http://www.forexfactory.com/showpost...1&postcount=13
Trailing Stoploss http://www.forexfactory.com/showpost...0&postcount=14
Break Even http://www.forexfactory.com/showpost...4&postcount=15

//----Questions & Answers----

coming soon...

//----Experts----

template.mq4 http://www.forexfactory.com/showpost...69&postcount=9

//----Indicators----

Macd

Attached File(s)

macd.mq4 6 KB | 351 downloads

Moving Average

Attached File(s)

moving average.mq4 3 KB | 373 downloads

//----Scripts-----

#2
Edited 10:01pm May 1, 2011 7:42pm | Edited 10:01pm

a_trader
| Joined Jun 2010 | Status: Trader | 113 Posts

The structure is the backbone to understanding programming.

Here is what you will see.

Inserted Code

if (this or that)do=this;

if (this or that){do=this;and_do_this=this;and_do this_to=this;}

so ...

Inserted Code

if (this or that)do=this;
if (this or that)do=this;
if (this or that)do=this;


if (this or that){do=these things;do=these things;do=these things;}

Look at it this way also

Inserted Code

if (this or that)
{
if (this or that)do=this;
if (this or that)do=this;
if (this or that)do=this;
  if (this or that)do=this;
  {
  if (this or that)do=this;
  if (this or that)do=this;
  }
}

For every { there must be a }
for every ( there must be a )

There will always be a even number of brackets!

Think of a building with many levels.
every time you have a { you go up the elevator one level.
every time you have a } you go down the elevator one level

There must always be the same amount of { as there is }

While you are on a floor, all of the () apply.

You must understand comments.
//this is a commented line
//any line starting with // is a comment
comments are a way of putting notes into our code

Here is a example

Inserted Code

if (were_on_floor_1)
 {//step up
do something=0;
   if (were_on_floor_2)
   {//step up
   do something=0;
      if (were_on_floor_3)
      {//step up
      do something=0;
      }//step down
   }//step down
 }//step down

#3
May 1, 2011 8:21pm May 1, 2011 8:21pm

newark18
| Joined Sep 2010 | Status: Trader | 371 Posts

I am so glad you started this thread. I am just learning code myself and find it hard finding answers to my questions. Thank you.

#4
May 1, 2011 8:23pm May 1, 2011 8:23pm

a_trader
| Joined Jun 2010 | Status: Trader | 113 Posts

More on basic structure

Here is a simple function that has 1 level

Inserted Code

function_1()
{

}

Here is a simple function that has 2 level's

Inserted Code

function_1()
{
if (something)
  {
  do something=0;
  }
}

Here is a simple function that has 3 level's

Inserted Code

function_1()
 {
 if (something)
  {
  do something=0;
    if (something)
       {
       do something=0;
       }
  }
 }

#5
May 1, 2011 8:25pm May 1, 2011 8:25pm

a_trader
| Joined Jun 2010 | Status: Trader | 113 Posts

Ask any questions you like.

Quoting newark18

Disliked

I am so glad you started this thread. I am just learning code myself and find it hard finding answers to my questions. Thank you.

Ignored

#6
May 1, 2011 8:48pm May 1, 2011 8:48pm

newark18
| Joined Sep 2010 | Status: Trader | 371 Posts

Here's one:

I would like to use sell and buy stops as entries but I would like to use the candle used for the entry to also be used for SLs. Assume that Candle1 has a buy stop at its high but entry doesn't happen immediately. Let's say it happens 4 candles later. How can I have the SL refer to the candle the buy stop was originally placed not the candle that the entry was made? I hope I was clear.

Do you have a good template that I can use to test simple systems? Ideally it has some functionality that I don't have to start from scratch. If not, no worries.

Thanks again!

#7
May 1, 2011 9:08pm May 1, 2011 9:08pm

a_trader
| Joined Jun 2010 | Status: Trader | 113 Posts

Variables tell us what type of data we are using.

Here are the types of variables you will see in mql4
int
double
string
color
time

int = a whole number (integer)
double = a number with a decimal
string = text
color = text (name of a color)
time = integers with commas, or without

Variables are usually declared at the top of the program, though they can be declared anywhere.

Variables are only available to functions depending on where they are declared.

A variable declared at the very top, is available to the entire program.
These variables are called global variables

A variable declared inside a function is only useable in that function, after it's declaration. These are called local variables.

although it confuses everything, in mql4 there is another variable called "global variables" which arent to do with the coding language, but a added feature of metatrader.
these variables shouldnt be confused, though they will be.

Example of variables

this is the diferent forms a variable can have, all being equal.

int orders;
int trades;

or...

int orders,trades;

or...

int orders=0;
int trades=0;

or...

int orders=0,trades=0;

#8
May 1, 2011 9:44pm May 1, 2011 9:44pm

a_trader
| Joined Jun 2010 | Status: Trader | 113 Posts

Im not giving you the exact code, but code you can edit.

just set the tp & sl after the order is opened.
A pending order counts.
Here is some code you can paste and edit.

Inserted Code

ticket=0;
ticket=OrderSend(Symbol(),OP_BUY,lots,Ask,3,NULL,NULL,NULL,NULL,0,Blue);
      if (ticket>0)
      {
      OrderSelect(ticket, SELECT_BY_TICKET);
OrderModify(OrderTicket(),OrderOpenPrice(),OrderOpenPrice()-sl*my_point,OrderOpenPrice()+tp*my_point,0,CLR_NONE);
ticket=0;
}

Quoting newark18

Disliked

Here's one:

I would like to use sell and buy stops as entries but I would like to use the candle used for the entry to also be used for SLs....

Ignored

#9
Edited 10:41pm May 1, 2011 9:54pm | Edited 10:41pm

a_trader
| Joined Jun 2010 | Status: Trader | 113 Posts

I do have a good template.
I was gonna bring it out later, but sooner might be better.

//----Edit----
I will explain more about this template while this post is editable.

This template is advanced, i have been working on it for about 5 years.
There is no bugs to date known.

As my knowledge in trading progressed, so did my strategies, I have removed most martingale and grid logic.

Using default settings there is no martingale or grid trading.
Any remnants of that code remaining will likely not function.

This ea has a goal system!
The goal code is unique, It takes your trading to a new level.

This template comes with the ability to trade on the chart using objects.
This feature also works in strategy tester.

//--------

Quoting newark18

Disliked

Here's one:
Do you have a good template that I can use to test simple systems? Ideally it has some functionality that I don't have to start from scratch. If not, no worries.

Thanks again!

Ignored

Attached File(s)

template.mq4 30 KB | 382 downloads

#10
May 1, 2011 10:08pm May 1, 2011 10:08pm

a_trader
| Joined Jun 2010 | Status: Trader | 113 Posts

this makes your code work on 4 & 5 digit brokers
by replacing Point with my_point

put this at the top

Inserted Code

double my_point;

put this inside init()

Inserted Code

if (Point==0.0001||Point==0.00001)my_point=0.0001;
   if (Point==0.01||Point==0.001)my_point=0.01;

Now just use my_point every where you would use Point.

heres anothe code you will need often
used in some maths, when drawing objects, and sometimes in money management code

at the top

Inserted Code

int digits;

inside the init()

Inserted Code

if (MarketInfo( Symbol(), MODE_LOTSTEP)==0.001)digits=3;
   if (MarketInfo( Symbol(), MODE_LOTSTEP)==0.01)digits=2;
   if (MarketInfo( Symbol(), MODE_LOTSTEP)==0.1)digits=1;
   if (MarketInfo( Symbol(), MODE_LOTSTEP)==1)digits=0;

heres some examples where i use this

Inserted Code

ObjectSetText("lots9","open lots "+DoubleToStr(buy_lots+sell_lots,digits)+"", 14,"Times New Roman",White);

Inserted Code

lots= NormalizeDouble(lots,digits);

heres example of using my_point

Inserted Code

spread=DoubleToStr((Ask-Bid)/my_point,1);

OrderModify(OrderTicket(),OrderOpenPrice(),center,OrderOpenPrice()+tp*my_point,0,CLR_NONE);

#11
May 1, 2011 10:14pm May 1, 2011 10:14pm

a_trader
| Joined Jun 2010 | Status: Trader | 113 Posts

put this at the top

Inserted Code

int ticket,current_bar;

Heres the code.

Inserted Code

if (!GlobalVariableCheck("current_bar"+WindowExpertName()+Symbol()+IsTesting()))
GlobalVariableSet("current_bar"+WindowExpertName()+Symbol()+IsTesting(),1);
current_bar=GlobalVariableGet("current_bar"+WindowExpertName()+Symbol()+IsTesting());
  if (signal=="buy"&&current_bar<iBarShift(NULL,0,0))
  {
   ticket=OrderSend(Symbol(),OP_BUY,lots,Ask,3,NULL,NULL,"trade_copy",NULL,0,Blue);
   if (ticket>0)
   {
   OrderSelect(ticket, SELECT_BY_TICKET);
   OrderModify(OrderTicket(),OrderOpenPrice(),Ask-stoploss*my_point,Ask+takeprofit*my_point,0,Blue);
   GlobalVariableSet("current_bar"+WindowExpertName()+Symbol()+IsTesting(),iBarShift(NULL,0,0));
   ticket=0;
   }
  }
  if (signal=="sell"&&current_bar<iBarShift(NULL,0,0))
  {
   ticket=OrderSend(Symbol(),OP_SELL,lots,Bid,3,NULL,NULL,"trade_copy",NULL,0,Red);
   if (ticket>0)
   {
   OrderSelect(ticket, SELECT_BY_TICKET);
   OrderModify(OrderTicket(),OrderOpenPrice(),Bid+stoploss*my_point,Bid-takeprofit*my_point,0,Red);
   GlobalVariableSet("current_bar"+WindowExpertName()+Symbol()+IsTesting(),iBarShift(NULL,0,0));
   ticket=0;
   }
  }

#12
May 1, 2011 10:20pm May 1, 2011 10:20pm

a_trader
| Joined Jun 2010 | Status: Trader | 113 Posts

orders should be counted before anything
they should also be re counted any time a trade is opened or closed
put this at the top

Inserted Code

int buys,sells,buy_pending,sell_pending;
double buy_lots,sell_lots;

put this in start() function

Inserted Code

orders();

put this at the very very bottom

Inserted Code

void orders()
{
buys=0;
sells=0;
buy_lots=0;
sell_lots=0;
buy_pending=0;
sell_pending=0;
  int totalorders = OrdersTotal();
  for(int i=totalorders-1;i>=0;i--)
 {
    OrderSelect(i, SELECT_BY_POS);
    if ( OrderType() == OP_BUY &&OrderSymbol()==Symbol())  
{buys++;buy_lots=buy_lots+OrderLots();}
    if ( OrderType() == OP_SELL&&OrderSymbol()==Symbol() )   
{sells++;sell_lots=sell_lots+OrderLots();}
    if (OrderSymbol()==Symbol()){
             if (OrderType() == OP_BUYLIMIT||OrderType() == 
OP_BUYSTOP) buy_pending++;
             if (OrderType() == OP_SELLLIMIT||OrderType() == 
OP_SELLSTOP) sell_pending++;
             }
 }
}

heres what you should have

Inserted Code

//+------------------------------------------------------------------+
//|                                              counting_orders.mq4 |
//|              Copyright © 2010, thomas liles, [email protected] |
//|                                       http://www.trendchaser.org |
//+------------------------------------------------------------------+
#property copyright "Copyright © 2010, thomas liles, [email protected]"
#property link      "http://www.trendchaser.org"
int buys,sells,buy_pending,sell_pending;
double buy_lots,sell_lots;
//+------------------------------------------------------------------+
//| expert initialization function                                   |
//+------------------------------------------------------------------+
int init()
  {
//----
   
//----
   return(0);
  }
//+------------------------------------------------------------------+
//| expert deinitialization function                                 |
//+------------------------------------------------------------------+
int deinit()
  {
//----
   
//----
   return(0);
  }
//+------------------------------------------------------------------+
//| expert start function                                            |
//+------------------------------------------------------------------+
int start()
  {
//----
   orders();
//----
   return(0);
  }
//+------------------------------------------------------------------+
void orders()
{
buys=0;
sells=0;
buy_lots=0;
sell_lots=0;
buy_pending=0;
sell_pending=0;
  int totalorders = OrdersTotal();
  for(int i=totalorders-1;i>=0;i--)
 {
    OrderSelect(i, SELECT_BY_POS);
    if ( OrderType() == OP_BUY &&OrderSymbol()==Symbol())  
{buys++;buy_lots=buy_lots+OrderLots();}
    if ( OrderType() == OP_SELL&&OrderSymbol()==Symbol() )   
{sells++;sell_lots=sell_lots+OrderLots();}
    if (OrderSymbol()==Symbol()){
             if (OrderType() == OP_BUYLIMIT||OrderType() == OP_BUYSTOP) buy_pending++;
             if (OrderType() == OP_SELLLIMIT||OrderType() == OP_SELLSTOP) sell_pending++;
             }
 }
}

#13
May 1, 2011 10:47pm May 1, 2011 10:47pm

a_trader
| Joined Jun 2010 | Status: Trader | 113 Posts

put these inside the start()

Inserted Code

close_all();
close_longs();
close_shorts();
close_all_in_profit();

put these at the very very bottom

Inserted Code

void close_all()
{
int totalorders = OrdersTotal();
 for(int i=totalorders-1;i>=0;i--)
 {
 OrderSelect(i, SELECT_BY_POS);
   if ( OrderSymbol()==Symbol())
   {
     if ( OrderType() == OP_SELL )  
     {
     OrderClose( OrderTicket(), OrderLots(), Ask, 0, Red );
     }
     if ( OrderType() == OP_BUY )   
     {
     OrderClose( OrderTicket(), OrderLots(), Bid, 0, Blue );
     }
   }
 }
}

Inserted Code

void close_longs()
{
int totalorders = OrdersTotal();
for(int i=totalorders-1;i>=0;i--)
{
OrderSelect(i, SELECT_BY_POS);
 if ( OrderSymbol()==Symbol())
 {
   if ( OrderType() == OP_BUY )   
   {
   OrderClose( OrderTicket(), OrderLots(), Bid, 0, Blue );
   }
 }
}
}

Inserted Code

void close_shorts()
{
int totalorders = OrdersTotal();
for(int i=totalorders-1;i>=0;i--)
{
OrderSelect(i, SELECT_BY_POS);
 if ( OrderSymbol()==Symbol())
 {
   if ( OrderType() == OP_SELL )  
   {
   OrderClose( OrderTicket(), OrderLots(), Ask, 0, Red );
   }
 }
}
}

Inserted Code

void close_all_in_profit()
{
int totalorders = OrdersTotal();
 for(int i=totalorders-1;i>=0;i--)
 {
 OrderSelect(i, SELECT_BY_POS);
   if ( OrderSymbol()==Symbol())
   {
     if ( OrderType() == OP_SELL && OrderProfit() > 0 )  
     {
     OrderClose( OrderTicket(), OrderLots(), Ask, 0, Red );
     }
     if ( OrderType() == OP_BUY && OrderProfit() > 0 )   
     {
     OrderClose( OrderTicket(), OrderLots(), Bid, 0, Blue );
     }
   }
 }
}

#14
May 1, 2011 10:50pm May 1, 2011 10:50pm

a_trader
| Joined Jun 2010 | Status: Trader | 113 Posts

at the top

Inserted Code

extern  double      TrailingStop= 20;

inside start() somewhere

Inserted Code

trail();

the function, at the very bottom

Inserted Code

void trail() 
  {
  for (int i = 0; i < OrdersTotal(); i++) {
     OrderSelect(i, SELECT_BY_POS, MODE_TRADES);
     
     if (OrderSymbol()==Symbol()  )  
        {
            if (OrderType() == OP_BUY) {
               if (Bid - OrderOpenPrice() > TrailingStop *my_point) {
                  if (OrderStopLoss() < Bid - TrailingStop * my_point) {
                     OrderModify(OrderTicket(), OrderOpenPrice(), Bid - TrailingStop * my_point, OrderTakeProfit(), Red);
                  }
               }
            } else if (OrderType() == OP_SELL) {
               if (OrderOpenPrice() - Ask > TrailingStop * my_point) {
                  if ((OrderStopLoss() > Ask + TrailingStop * my_point) || 
                        (OrderStopLoss() == 0)) {
                     OrderModify(OrderTicket(), OrderOpenPrice(),
                        Ask + TrailingStop * my_point, OrderTakeProfit(), Red);  
                  }
               }
            }
        }
     }
 }

#15
May 1, 2011 10:53pm May 1, 2011 10:53pm

a_trader
| Joined Jun 2010 | Status: Trader | 113 Posts

put this at the top

Inserted Code

[size=2][color=#000000][/color][/size]
extern  bool        use_breakeven=false;// standard break even
extern int         BreakEven= 20;

put inside start()

Inserted Code

breakeven();

the function

Inserted Code

void breakeven()
{
 int totalorders = OrdersTotal();
 for(int i=totalorders-1;i>=0;i--)
{
   OrderSelect(i, SELECT_BY_POS);
   bool result = false;
   if (OrderSymbol()==Symbol())
    {
          if ( OrderType() == OP_BUY &&High[0]-OrderOpenPrice()>=BreakEven*my_point && OrderStopLoss()
<OrderOpenPrice())  
          result = OrderModify(OrderTicket(),OrderOpenPrice(),OrderOpenPrice(),OrderTakeProfit(),0,Red);
          if ( OrderType() == OP_SELL &&OrderOpenPrice()-Low[0]>=BreakEven*my_point && OrderStopLoss()
>OrderOpenPrice())  
          result = OrderModify(OrderTicket(),OrderOpenPrice(),OrderOpenPrice(),OrderTakeProfit(),0,Red);
     }
 }
 return;
}

#16
Edited 11:27pm May 1, 2011 10:53pm | Edited 11:27pm

nubcake
Joined Oct 2009 | Status: . | 4,038 Posts

am i going to be the dark cloud in your sunny day? yes.

why are you writing this stuff? there IS a help file with mt4 for coding in mql. there is an entire mql forum dedicated to learning the ins and outs of aspects of mql.

why are you trying to teach stuff if you aren't teaching it correctly? levels for { } sections, double is a number with a decimal point, the whole my_point bit... it's all half-right and half-wrong. you are effectively mis-teaching. you might be able to kickstart someones mql journey, but there are better teachings already online ready to go. i wonder if you are just trying to boost your post count for some reason.

and the my_point bit annoys me enough for me to correct this one detail. your whole my_point to get around 4 and 5 digit brokers is simply wrong. a point is a point. no more, no less. it is the smallest step-size allowed for the current chart as per the broker. what you are trying to do with your my_point variable is actually represent correctly 1 pip. PIP... NOT POINT! this is a major difference. it might seem like it's simply symantics and unimportant, but it's like calling a dog a cat. The whole reason the Point and Digits functions exist is so that you can on one hand detect how many digits your broker is using and also so that you can then correctly scale any further maths from that if needed. It allows you to easily calculate from the smallest available granularity as well as detect what that granularity is.

what you are doing is like giving floaties to people who can't swim to help them get started (great) but then letting them swim in a shark and crocodile infested olympic pool (not so great). mql is a crappy scripting language filled with fundamental problems that experienced REAL LIFE coders (not scripters) come across and then have to understand and find workarounds for, so to teach what are meant to be coding concepts in the framework of the flawed mql environment and not even teach them correctly is just plain bad.

anyway... enough said.

Congratulations ScalaFX for coming out of the closet!

#17
May 1, 2011 11:16pm May 1, 2011 11:16pm

a_trader
| Joined Jun 2010 | Status: Trader | 113 Posts

I guess your right.
I dont know programming.
I taught my self everything, so i am probably wrong on alot.
I didnt go to school, I am definatly a rebel.
Sorry if i mis teached anyone.

Quoting nubcake

Disliked

am i going to be the dark could in your sunny day?...

Ignored

#18
May 1, 2011 11:26pm May 1, 2011 11:26pm

nubcake
Joined Oct 2009 | Status: . | 4,038 Posts

Quoting zznbrm

Disliked

Excuse me...Mr. Perfect...can you take a few minutes from your busy day up there on Mount Olympus and explain to us mere mortals what a "dark could" is ?

Ignored

a dark could is about 16 hours of being awake and blurry eyes. also known as a typo. now if you have finished being sarcastic you can return to learning how to do things wrong. enjoy.

Congratulations ScalaFX for coming out of the closet!

#19
May 1, 2011 11:42pm May 1, 2011 11:42pm

nubcake
Joined Oct 2009 | Status: . | 4,038 Posts

Quoting a_trader

Disliked

I guess your right.
I dont know programming.
I taught my self everything, so i am probably wrong on alot.
I didnt go to school, I am definatly a rebel.
Sorry if i mis teached anyone.

Ignored

in the best possible way of saying this... it shows. if you had been taught i would expect that the way you frame the concepts to be much different. no one taught me either, but coming from years of programming real executables and not some hokey mql script means i've been exposed to the real stuff for a long time, and i'm no expert either.

like i said, you are half-right with your explanations etc, but only half. explaining bracketed sections is misleading at best. what happens when you "go up a level" in one section and then it finishes so you return down a level but then further down the script you "go up a level" again? how does this relate to the first time you went up a level? programmatically they are unrelated, and so the concept is wrong and doesn't describe the process at all well.

i think you have figured out some stuff and want to get amongst it with others. this thread would perhaps better serve as an avenue for people (like newark) to come and ask newbie scripting questions for you to tackle and work-out communally with them.

i'm going to try to shut up now. i butt-in here not to troll, but because it's a lot like watching people driving along the road but start to drift off the road and not even know it. after awhile they are so far off the road they don't know where it even is and are lost in the forest going the wrong direction and into a minefield. being anal about staying on the road keeps everything clear and accurate.

Congratulations ScalaFX for coming out of the closet!

#20
May 1, 2011 11:44pm May 1, 2011 11:44pm

nubcake
Joined Oct 2009 | Status: . | 4,038 Posts

Quoting zznbrm

Disliked

I've never heard of that term before. Reminds me of my college days...I had lots of dark coulds back then!

You should really try to get more rest...too many dark coulds can be bad for you.

Ignored

that's what the mirror says. if you ever speak to my sleep-cycle make sure you let it know because it doesn't listen to me.

Congratulations ScalaFX for coming out of the closet!

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