MQL4｜How to Normalize Double Type (Double) in MetaTrader 4 (MT4) MQL4 Programs

In MetaTrader 4 (MT4) MQL4 programs, it is common to round double type values to a specified number of decimal places. This article explains how to normalize double type values using the NormalizeDouble function in a way that is easy for beginners to understand.

What is Normalization?

Normalization refers to rounding double type values to a specified number of decimal places. This allows for handling values with a specific precision. For example, it is useful in cases where specific precision is required, such as stop values and limit values when placing orders.

Using the NormalizeDouble Function

To normalize double type values, use the NormalizeDouble function. This function rounds values to a specified number of decimal places.

Function Specification

double NormalizeDouble(double value, int digits)

• value: The value to be normalized.
• digits: The number of decimal places (0 to 8).

Sample Code

Below is a sample code that normalizes a double type value using the NormalizeDouble function.

double original_value = 0.123456789;
double normalized_value = NormalizeDouble(original_value, 5);
Print("Normalized value: " + DoubleToStr(normalized_value, 8));

Execution Result

Running the above sample code will yield the following result:

Normalized value: 0.12346000

Example of Usage

Below is an example of how to use the NormalizeDouble function in an actual trading program.

Usage Example When Placing Orders

double stop_loss = 0.987654321;
double take_profit = 1.123456789;

// Normalize stop loss and take profit values to 5 digits
stop_loss = NormalizeDouble(stop_loss, 5);
take_profit = NormalizeDouble(take_profit, 5);

// Place order
int ticket = OrderSend(Symbol(), OP_BUY, 1.0, Ask, 3, stop_loss, take_profit, "Sample Order", 0, 0, Blue);
if(ticket < 0) {
    Print("Order send error: " + ErrorDescription(GetLastError()));
} else {
    Print("Order send success: " + ticket);
}

In this example, the stop loss and take profit values are normalized to 5 digits when placing an order. This ensures that the order is placed with the appropriate precision.

Summary

By using the NormalizeDouble function, you can normalize double type values to a specified number of decimal places. This allows you to handle values with specific precision, enabling accurate value processing in trading programs. Beginners should first learn the basic usage of this function and apply it to actual programs.