How to draw a box in MT4?

>> By the way... do you understand clearly how the indicator works? <<

Of course not.

>> Before building any EA you should try to build small custom indicator.<<

I am notorious for getting wayy over my head into subject matters that attract me. (like writing EA's) Its extremely confusing at first but eventually things will make sense and wala! youre an expert! I will go to step one after I have inspected steps 3 through 5. But I do not ignore advise from the more experienced. So I will take youre advise and play with the RSI indicator first. For now I will lay the EA to rest while I learn more basic things ...

>> put the real indicator and your custom indicator side by side and see if you have done the right thing<<

This seems like a good idea..

Thanks again for your help and patience with me.

I can help you to build your first indicator and show the basic...
Of course you will have to do your lesson by looking at the cours(pdf) to deeply understand everything...

Step 1-

 

1. Create a blank, Custom Indicator (File->new->Custom indicator)
2. Give it a name you like(A name that does not exist)
3. Leave for now everything by default(Do next)

Then write nothing, Compile the indicator by doing F5
It should buy now be in you MT4 Custom list
And we will start from there...

If you want of course!!! :-)

Yes of course I want to!!

I have followed your instructions to the letter.

I have my new indicator called IndicatorProto001.mq4 in my "Indicators" folder.

Ready for next step when you are. In the mean time I will be re-reading lessons 10 through 12 that speak to the indicator.

1. #property copyright ""
2. #property link ""

1 and 2 are there to only identify your script (Not important for coding)

3. #property indicator_chart_window

Each windows as a value, the windows with chart is 0 then each indicator at the bottom receive value 1 to x.

So if you create a indicator with indicator_chart_window, the graphic will be place in the windows #0 (The chart window).
If you use indicator_separate_window then it will create the indicator in a seperate windows like MACD or RSI...
- So for the perpose of creating a RSI look alike you need to change it to indicator_separate_window
- By the way, it could have been done in the Wizard(Check Box)

#property are there to define various aspect off your indicator, will see later...

4. int init()

Init is where you put your code that must be initialized when the indicator is loaded. Like Buffer or Global Variable it is only done once...

5. int deinit()

deinit is the reverse of init. So it will be executed when the indicator is remove from the chart.
Exemple if you put text object on the chart window, you want them to be remove when you remove the indicator or they will be left there.

6. int start()

after init as been call and everytime a new input(Every tick value) comes in, then the application execute the start function...

Thats it for the base...

Now Exemple.:

If you declare a global variable above init(Not inside the function, see below) like double test=0; then in the init you put test=1; and in the start you put test = 2;
Then when you load your indicator the test will receive 1 as value;
and everytime the start is triggered, test will receive 2 as value

double test=0;
int init(){ test=1; Comment("test:",test);}
int start(){ test=2; Comment("test:",test ); }

Ps.:
Comment is use to put Text on the windows chart left corner and Print in the Terminal window under expert tab.
Also if you remove test from start you will see that it will output always 1
The way is emplemented is useless since it will do init and start imediately, so test will always have 2.But its just to show how init and start work for basic.


Ps.: For those that read this... this is just a basic explaination. It is not my attention to create a lessons... Go see this thread. It is well done.

By the way notify me when you read and understand. So i can continue... i will wait before going on and on and on and on....

Had to read it a few times but I think I understand this at this point.

Feel free to continue at will.

Ok. so resume
Init <- the program will execute this function only once(When indicator is loaded)
deInit <- the program will execute this function only once(When indicator is unloaded)
Start <- the program will execute this function each time the it receive data from the server.

Now, what is the custom indicator?
To make it short. The main reason is to build custom indicator(CI for now on) is to put a idea in a graphical way (And yes you can do more, sound, export, file read/write, alert, etc.).

But before...
CI use Array(Or buffer or table) . What are they?
You should know what is a variable(If not, go read about it).
Imagine you want to declare 100 variables(variable1,varaiable2, etc..).
It will take to much time and effort to do so...

So Array are just multiple variable combine under one name( Again, its more than that, but for now its enough).
Imagine 100 box next to each other. the first one is 0, the 1, then 2, etc...
(Array start at 0 to (Array size) -1)
If you want to get/write value from Box #5 then you use Box[4] ( Box[BoxSize-1] )

Normaly, you will define the size of the buffer when you declare it. Because the program dont know how much size you want!

___
To make a short story: the program must allocate, in memory, the space needed by the buffer ( ex.: int buffer[2]={1,2}; will create 2 space of int type in memory). When you declare a variable (int test, the program will automaticaly allocate 1 space of type 'int' to receive the information.
(Also you can expand or retract buffer in you code:But for now forget about it).
___

CI show graphic. Then you must use a Buffer to do so. CI will use the Buffer you tell him to use. There is a maximum of 8 buffer to use for the indicator(But you can use many table, youl see later).

Each box(to make sample explanaton) equal to 1 candle on the graphic.
Buffer[0] is align with Candle #0 and so on...
Starting from right to left(Most recent to the oldest)

The line are draw from one box to the other: if you have 10 in box[0] and 5 in box[1], the line will go from right to left, from 10 to 5(Up line).

For the first demo we wil just put 1 as the value in the indicator(Flat line).

Here we go:

First we put the '#property', property of the CI

#property indicator_separate_window
#property indicator_minimum 0
#property indicator_maximum 2
#property indicator_buffers 1
#property indicator_color1 Red

'indicator_minimum' and 'indicator_maximum' will define the scale(Values at the right of the CI). If you remove 'indicator_minimum' and 'indicator_maximum' it will you the High and low from value in the CI Buffer to scale it. ( with only 1 as the value like her demo if you dont put min/max you will not see the flat line)

'indicator_buffers' is use to tell the program how much buffer we will use to output graphic(how much lines we wants:max 8).

'indicator_color1' is easy, is to tell the color you want for you lines.

Below all '#property' you put

double ExtMapBuffer1[];

'ExtMapBuffer1' is te default name put by the wizard , but i change it everytime; Lets says Buffer[];
In this case you dont have to say how much space we need(Buffer[x],
because it will be done on the 'Init' function;

In the init function you put:

SetIndexStyle(0,DRAW_LINE);
SetIndexBuffer(0,ExtMapBuffer1);

'SetIndexStyle' is use to define the type of graphics(line, histograme, etc...)
0 represent the first buffer you initialize, it will take the 'indicator_color1',and #1 will use 'indicator_color2', etc to associate the color...

The order you put the buffer is not so important, but it will draw them one after the other, so 0 will be under 1, so 2 will be on top of 1,etc. Now imagine a MACD, if the MACD line is behind the histogram! Its just a matter of visibility.(But it must be from 0 to x)

'SetIndexBuffer' associate 'ExtMapBuffer1' to 0 and use this to indentify the buffer and use it to paint the line on the CI.

So thats it. you have your base declaration...
Now lets use it...

Put in the 'start' function:

int limit = Bars-IndicatorCounted();
for(int x=limit ; x >=0 ; x--){
ExtMapBuffer1[x]=1;
}

Your done...
For any info on the function ot other stuff. Double click on it then 'F1'
Try it... and tell me if it work... you will have your flat line...

Hey! it worked! i got my flat red line.

There is a good deal of substance in this last post for me to digest. I will go over it several times to understand well everything that is happening.

Thanks for taking the time to do this man. Markets are closed and the holiday is upon us. Hope you and yours have a great Holiday and Happy New Year!

Hal

Now below

double ExtMapBuffer1[];

Add

extern int MyPeriod = 21;

extern is use to interact with the indicator, when you install the CI you have a pop-up, then in the input tab you see your extern variable...

Now replace the ExtMapBuffer1[x]=1;
with:

ExtMapBuffer1[x]= iRSI(NULL,0,MyPeriod ,PRICE_CLOSE,x) ;

remove :

#property indicator_minimum 0
#property indicator_maximum 2

And compile... If you see nothing. thats ok. remove the indicator and put it back... The scale does not change when you compile.because the RSI value is not fiting between 0 and 2...

Here you go...
Now you have your basic...
Try to modify value, add buffer, change color, use other indicator(Instead of RSI, use iCCI), All you have to know is there to begin...

After will see...
if you have other question, go ahead... :-)

Happy holidays

I’ve done as you instructed and edited the CI

Compiled with no errors and when I applied it to the chart I see that it mimics identically to the RSI(21) that I have running on the same chart.

Here is what I could understand so far:

For a CI, all this:

#property indicator_separate_window
#property indicator_buffers 1
#property indicator_color1 Red

is applied to this:

double ExtMapBuffer1[];

and this:

extern int MyPeriod = 21;

is just an external variable. ( I understand what a variable is. External makes it so you can set it in the little GUI when its started.)

This here:

int init()
{
SetIndexStyle(0,DRAW_LINE);
SetIndexBuffer(0,ExtMapBuffer1);

return(0);
}

This says what will be graphically drawn and is in the “run one time at startup” section. In this case, draw a line that starts at 0 and uses the following buffer to draw itself [ buffer = ( starting from 0 is the value of ExtMapBuffer1) ]

Then we go all the way down to the “start” part of the script and here we have....

int start()
{
int limit = Bars-IndicatorCounted(); /*Declare integer constant that equals to the result of (Number of bars in the counted chart MINUS the amount of bars not changed after the indicator had been launched last) */
for(int x=limit ; x >=0 ; x--) /* For ( declare integer “x” that equals “limit” and “x” is greater than or equal to zero, decrease “x” by one.) Does this make it so that the shit starts at 0 and goes back by one each time. (?) */
{
ExtMapBuffer1[x]=iRSI(NULL,0,MyPeriod ,PRICE_CLOSE,x); /* ExtMapBuffer1[x] equals iRSI(......,x) */
}


I am going over each line of code slowly to understand it good and changing indicator, color, buffers, etc. like you advise. Its slowly starting to sink in. I am sure I will have more questions in a short time.

This is about as detailed an explanation as anyone could ask for. I am thankful that you have taken the time to explain this mundane details to a newbie. Great karma to you! Thanks again man!

Hal

I have kept working on this and its making sense!

I wrote my first EA and I think I hit beginners luck in a big way! Thank you so much for your good instructions! I could not have done it without you.

I know this is the begining of a long journey. I dont expect miracles right away. But I am forward testing my oddity of nature now and so far it works fantastic! (on demo FXDD account)
I call it an odity of nature because someone with such little MQL4 experience should not be able to write something that actually works so well in forward testing.

180 pips in last 24 hrs. of FWD testing on demo (beginners luck, its only one day.)

http://www.venexys.com/HP002A2_FWD_DET_TEST_DAY001.gif
http://www.venexys.com/HP002A2_FWD_TEST_RESULTS.htmhttp://www.venexys.com/HP002A2_FWD_TEST_RESULTS.htm

Some clarification need to be done:
Wrong(Well just to not get you confused):
#property indicator_separate_window <-Is were the CI will be
#property indicator_buffers 1 <- Just tell how much buffer there is
Because sometime you will have more buffer but only 1 or 2 to be draw...
#property indicator_color1 Red <- Tell the API to use red for the first line buffer

Wrong:
SetIndexBuffer(0,ExtMapBuffer1);<- 0 is only for the first buffer to be draw, 1 would be the second the be draw ( In stochastic, you have 0,1 because of the 2 line)
SetIndexStyle(0,DRAW_LINE);<- DRAW_LINE will be apply to buffer defined by 0 so ExtMapBuffer1

It goes from left to right: so the last bar(Oldest) to the most recent one (0:Current)

Ps.: EA are not perfect, they are some error, like Close.
If you use Close[x] or indicator that use Close price on current bar you will have invalid data...

Why? in EA the Current bar does not have a Close Value just the Open,
So if you use RSI by exemple, RSI[0] will not give a good value until RSI[1],
Because RSI use PRICE_CLOSE to calculate is stuff....

So EA are good but to just help us define strategie, it must be tested live...

Thank you for your clarifications. I will make sure I understand them.

Hal