MQL4 and MQL5 Programming Articles

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Study the MQL5 language for programming trading strategies in numerous published articles mostly written by you - the community members. The articles are grouped into categories to help you quicker find answers to any questions related to programming: Integration, Tester, Trading Strategies, etc.

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Learn how to design a trading system by Gator Oscillator

Learn how to design a trading system by Gator Oscillator

A new article in our series about learning how to design a trading system based on popular technical indicators will be about the Gator Oscillator technical indicator and how to create a trading system through simple strategies.
Tracing, Debugging and Structural Analysis of Source Code
Tracing, Debugging and Structural Analysis of Source Code

Tracing, Debugging and Structural Analysis of Source Code

The entire complex of problems of creating a structure of an executed code and its tracing can be solved without serious difficulties. This possibility has appeared in MetaTrader 5 due to the new feature of the MQL5 language - automatic creation of variables of complex type of data (structures and classes) and their elimination when going out of local scope. The article contains the description of the methodology and the ready-made tool.
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Creating an EA that works automatically (Part 06): Account types (I)

Creating an EA that works automatically (Part 06): Account types (I)

Today we'll see how to create an Expert Advisor that simply and safely works in automatic mode. Our EA in its current state can work in any situation but it is not yet ready for automation. We still have to work on a few points.
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Brute force approach to pattern search (Part II): Immersion

Brute force approach to pattern search (Part II): Immersion

In this article we will continue discussing the brute force approach. I will try to provide a better explanation of the pattern using the new improved version of my application. I will also try to find the difference in stability using different time intervals and timeframes.
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Revisiting an Old Trend Trading Strategy: Two Stochastic oscillators, a MA and Fibonacci

Revisiting an Old Trend Trading Strategy: Two Stochastic oscillators, a MA and Fibonacci

Old trading strategies. This article presents one of the strategies used to follow the trend in a purely technical way. The strategy is purely technical and uses a few technical indicators and tools to deliver signals and targets. The components of the strategy are as follows: A 14-period stochastic oscillator. A 5-period stochastic oscillator. A 200-period moving average. A Fibonacci projection tool (for target setting).
Optimal approach to the development and analysis of trading systems
Optimal approach to the development and analysis of trading systems

Optimal approach to the development and analysis of trading systems

In this article, I will show the criteria to be used when selecting a system or a signal for investing your funds, as well as describe the optimal approach to the development of trading systems and highlight the importance of this matter in Forex trading.
LibMatrix: Library of Matrix Algebra (Part One)
LibMatrix: Library of Matrix Algebra (Part One)

LibMatrix: Library of Matrix Algebra (Part One)

The author familiarizes the readers with a simple library of matrix algebra and provides descriptions and peculiarities of the main functions.
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Magic of time trading intervals with Frames Analyzer tool

Magic of time trading intervals with Frames Analyzer tool

What is Frames Analyzer? This is a plug-in module for any Expert Advisor for analyzing optimization frames during parameter optimization in the strategy tester, as well as outside the tester, by reading an MQD file or a database that is created immediately after parameter optimization. You will be able to share these optimization results with other users who have the Frames Analyzer tool to discuss the results together.
Interview with Juan Pablo Alonso Escobar (ATC 2012)
Interview with Juan Pablo Alonso Escobar (ATC 2012)

Interview with Juan Pablo Alonso Escobar (ATC 2012)

"Everyone who is struggling with programming and who were not able to participate in this year's competition, know that it becomes a lot easier in time", said Juan Pablo Alonso Escobar (JPAlonso), the hero of today's interview.
Graphics in DoEasy library (Part 94): Moving and deleting composite graphical objects
Graphics in DoEasy library (Part 94): Moving and deleting composite graphical objects

Graphics in DoEasy library (Part 94): Moving and deleting composite graphical objects

In this article, I will start the development of various composite graphical object events. We will also partially consider moving and deleting a composite graphical object. In fact, here I am going to fine-tune the things I implemented in the previous article.
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Simple Mean Reversion Trading Strategy

Simple Mean Reversion Trading Strategy

Mean reversion is a type of contrarian trading where the trader expects the price to return to some form of equilibrium which is generally measured by a mean or another central tendency statistic.
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A Step-by-Step Guide on Trading the Break of Structure (BoS) Strategy

A Step-by-Step Guide on Trading the Break of Structure (BoS) Strategy

A comprehensive guide to developing an automated trading algorithm based on the Break of Structure (BoS) strategy. Detailed information on all aspects of creating an advisor in MQL5 and testing it in MetaTrader 5 — from analyzing price support and resistance to risk management
Graphics in DoEasy library (Part 89): Programming standard graphical objects. Basic functionality
Graphics in DoEasy library (Part 89): Programming standard graphical objects. Basic functionality

Graphics in DoEasy library (Part 89): Programming standard graphical objects. Basic functionality

Currently, the library is able to track standard graphical objects on the client terminal chart, including their removal and modification of some of their parameters. At the moment, it lacks the ability to create standard graphical objects from custom programs.
How to Develop a Reliable and Safe Trade Robot in MQL 4
How to Develop a Reliable and Safe Trade Robot in MQL 4

How to Develop a Reliable and Safe Trade Robot in MQL 4

The article deals with the most common errors that occur in developing and using of an Expert Advisor. An exemplary safe automated trading system is described, as well.
Other classes in DoEasy library (Part 70): Expanding functionality and auto updating the chart object collection
Other classes in DoEasy library (Part 70): Expanding functionality and auto updating the chart object collection

Other classes in DoEasy library (Part 70): Expanding functionality and auto updating the chart object collection

In this article, I will expand the functionality of chart objects and arrange navigation through charts, creation of screenshots, as well as saving and applying templates to charts. Also, I will implement auto update of the collection of chart objects, their windows and indicators within them.
Filtering Signals Based on Statistical Data of Price Correlation
Filtering Signals Based on Statistical Data of Price Correlation

Filtering Signals Based on Statistical Data of Price Correlation

Is there any correlation between the past price behavior and its future trends? Why does the price repeat today the character of its previous day movement? Can the statistics be used to forecast the price dynamics? There is an answer, and it is positive. If you have any doubt, then this article is for you. I'll tell how to create a working filter for a trading system in MQL5, revealing an interesting pattern in price changes.
Expert Advisors Based on Popular Trading Systems and Alchemy of Trading Robot Optimization (Part II)
Expert Advisors Based on Popular Trading Systems and Alchemy of Trading Robot Optimization (Part II)

Expert Advisors Based on Popular Trading Systems and Alchemy of Trading Robot Optimization (Part II)

In this article the author continues to analyze implementation algorithms of simplest trading systems and describes some relevant details of using optimization results. The article will be useful for beginning traders and EA writers.
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Neural networks made easy (Part 13): Batch Normalization

Neural networks made easy (Part 13): Batch Normalization

In the previous article, we started considering methods aimed at improving neural network training quality. In this article, we will continue this topic and will consider another approach — batch data normalization.
MQL4 Language for Newbies. Difficult Questions in Simple Phrases.
MQL4 Language for Newbies. Difficult Questions in Simple Phrases.

MQL4 Language for Newbies. Difficult Questions in Simple Phrases.

This is the second article from the series "MQL4 Language for Newbies". Now we will examine more complex and advanced constructions of the language, learn new options and see, how they can be applied in everyday practice. You will get acquainted with a new cycle type 'while', new condition type 'switch', operators 'break' and 'continue'. Besides you will learn to write your own functions and work with multidimensional arrays. And for a dessert I have prepared an explanation about a preprocessor.
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Gradient boosting in transductive and active machine learning

Gradient boosting in transductive and active machine learning

In this article, we will consider active machine learning methods utilizing real data, as well discuss their pros and cons. Perhaps you will find these methods useful and will include them in your arsenal of machine learning models. Transduction was introduced by Vladimir Vapnik, who is the co-inventor of the Support-Vector Machine (SVM).
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Deep Learning Forecast and ordering with Python and MetaTrader5 python package and ONNX model file

Deep Learning Forecast and ordering with Python and MetaTrader5 python package and ONNX model file

The project involves using Python for deep learning-based forecasting in financial markets. We will explore the intricacies of testing the model's performance using key metrics such as Mean Absolute Error (MAE), Mean Squared Error (MSE), and R-squared (R2) and we will learn how to wrap everything into an executable. We will also make a ONNX model file with its EA.
Prices in DoEasy library (part 60): Series list of symbol tick data
Prices in DoEasy library (part 60): Series list of symbol tick data

Prices in DoEasy library (part 60): Series list of symbol tick data

In this article, I will create the list for storing tick data of a single symbol and check its creation and retrieval of required data in an EA. Tick data lists that are individual for each used symbol will further constitute a collection of tick data.
Library for easy and quick development of MetaTrader programs (part IX): Compatibility with MQL4 - Preparing data
Library for easy and quick development of MetaTrader programs (part IX): Compatibility with MQL4 - Preparing data

Library for easy and quick development of MetaTrader programs (part IX): Compatibility with MQL4 - Preparing data

In the previous articles, we started creating a large cross-platform library simplifying the development of programs for MetaTrader 5 and MetaTrader 4 platforms. In the eighth part, we implemented the class for tracking order and position modification events. Here, we will improve the library by making it fully compatible with MQL4.
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Population optimization algorithms: Particle swarm (PSO)

Population optimization algorithms: Particle swarm (PSO)

In this article, I will consider the popular Particle Swarm Optimization (PSO) algorithm. Previously, we discussed such important characteristics of optimization algorithms as convergence, convergence rate, stability, scalability, as well as developed a test stand and considered the simplest RNG algorithm.
MQL5 Programming Basics: Global Variables of the Terminal
MQL5 Programming Basics: Global Variables of the Terminal

MQL5 Programming Basics: Global Variables of the Terminal

This article highlights object-oriented capabilities of the MQL5 language for creating objects facilitating work with global variables of the terminal. As a practical example I consider a case when global variables are used as control points for implementation of program stages.
Calculation of Integral Characteristics of Indicator Emissions
Calculation of Integral Characteristics of Indicator Emissions

Calculation of Integral Characteristics of Indicator Emissions

Indicator emissions are a little-studied area of market research. Primarily, this is due to the difficulty of analysis that is caused by the processing of very large arrays of time-varying data. Existing graphical analysis is too resource intensive and has therefore triggered the development of a parsimonious algorithm that uses time series of emissions. This article demonstrates how visual (intuitive image) analysis can be replaced with the study of integral characteristics of emissions. It can be of interest to both traders and developers of automated trading systems.
Library for easy and quick development of MetaTrader programs (part VI): Netting account events
Library for easy and quick development of MetaTrader programs (part VI): Netting account events

Library for easy and quick development of MetaTrader programs (part VI): Netting account events

In the previous articles, we started creating a large cross-platform library simplifying the development of programs for MetaTrader 5 and MetaTrader 4 platforms. In the fifth part of the article series, we created trading event classes and the event collection, from which the events are sent to the base object of the Engine library and the control program chart. In this part, we will let the library to work on netting accounts.
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Learn how to design a trading system by Bill Williams' MFI

Learn how to design a trading system by Bill Williams' MFI

This is a new article in the series in which we learn how to design a trading system based on popular technical indicators. This time we will cover Bill Williams' Market Facilitation Index (BW MFI).
Graphics in DoEasy library (Part 80): "Geometric animation frame" object class
Graphics in DoEasy library (Part 80): "Geometric animation frame" object class

Graphics in DoEasy library (Part 80): "Geometric animation frame" object class

In this article, I will optimize the code of classes from the previous articles and create the geometric animation frame object class allowing us to draw regular polygons with a given number of vertices.
Running MetaTrader 4 Client Terminal on Linux-Desktop
Running MetaTrader 4 Client Terminal on Linux-Desktop

Running MetaTrader 4 Client Terminal on Linux-Desktop

Description of a step-by-step Linux-desktop setup using a non-emulator wine for running MetaTrader 4 Client Terminal on it.
Jeremy Scott - Successful MQL5 Market Seller
Jeremy Scott - Successful MQL5 Market Seller

Jeremy Scott - Successful MQL5 Market Seller

Jeremy Scott who is better known under Johnnypasado nickname at MQL5.community became famous offering products in our MQL5 Market service. Jeremy has already made several thousands of dollars in the Market and that is not the limit. We decided to take a closer look at the future millionaire and receive some pieces of advice for MQL5 Market sellers.
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Data Science and Machine Learning (Part 04): Predicting Current Stock Market Crash

Data Science and Machine Learning (Part 04): Predicting Current Stock Market Crash

In this article I am going to attempt to use our logistic model to predict the stock market crash based upon the fundamentals of the US economy, the NETFLIX and APPLE are the stocks we are going to focus on, Using the previous market crashes of 2019 and 2020 let's see how our model will perform in the current dooms and glooms.
Drawing Horizontal Break-Through Levels Using Fractals
Drawing Horizontal Break-Through Levels Using Fractals

Drawing Horizontal Break-Through Levels Using Fractals

The article describes creation of an indicator that would display the support/resistance levels using up/down fractals.
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Matrix and Vector operations in MQL5

Matrix and Vector operations in MQL5

Matrices and vectors have been introduced in MQL5 for efficient operations with mathematical solutions. The new types offer built-in methods for creating concise and understandable code that is close to mathematical notation. Arrays provide extensive capabilities, but there are many cases in which matrices are much more efficient.
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Indicators with on-chart interactive controls

Indicators with on-chart interactive controls

The article offers a new perspective on indicator interfaces. I am going to focus on convenience. Having tried dozens of different trading strategies over the years, as well as having tested hundreds of different indicators, I have come to some conclusions I want to share with you in this article.
What Is a Martingale?
What Is a Martingale?

What Is a Martingale?

A short description of various illusions that come up when people trade using martingale betting strategies or misuse spiking and the like approaches.
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Data Science and Machine Learning (Part 09): The K-Nearest Neighbors Algorithm (KNN)

Data Science and Machine Learning (Part 09): The K-Nearest Neighbors Algorithm (KNN)

This is a lazy algorithm that doesn't learn from the training dataset, it stores the dataset instead and acts immediately when it's given a new sample. As simple as it is, it is used in a variety of real-world applications.
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Developing a Replay System — Market simulation (Part 03): Adjusting the settings (I)

Developing a Replay System — Market simulation (Part 03): Adjusting the settings (I)

Let's start by clarifying the current situation, because we didn't start in the best way. If we don't do it now, we'll be in trouble soon.
Building an Interactive Application to Display RSS Feeds in MetaTrader 5
Building an Interactive Application to Display RSS Feeds in MetaTrader 5

Building an Interactive Application to Display RSS Feeds in MetaTrader 5

In this article we look at the possibility of creating an application for the display of RSS feeds. The article will show how aspects of the Standard Library can be used to create interactive programs for MetaTrader 5.
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Building and testing Aroon Trading Systems

Building and testing Aroon Trading Systems

In this article, we will learn how we can build an Aroon trading system after learning the basics of the indicators and the needed steps to build a trading system based on the Aroon indicator. After building this trading system, we will test it to see if it can be profitable or needs more optimization.