This ProBuilder code snippet demonstrates how to create and use a custom function to check if a given number falls within a specified range. The function, named `MyRange`, determines whether a value `x` is within a certain distance `z` from a base value `y`. This is useful in trading strategies for validating conditions based on price or other numerical indicators.

Code for the `MyRange` Function:

// MyRange
// indicator to be installed with ProBuilder and be called by strategies
// input:
// x = number to be checked against a range
// y = base to define a range (+/- z)
// z = range within which x will be validated or not
//
// returns:
// 0 = x is NOT within range z
// 1 = x is within above said range
IF x >= (y - z) AND x <= (y + z) THEN
    Result = 1 //X is within range y-z through y+z
ELSE
    Result = 0 //X is not within the above said range
ENDIF
RETURN Result

#### Code for Testing the `MyRange` Function:

// MyStrategy
x = close
y = close + (0.3 * pipsize)
z = 0.5 * pipsize
a = CALL MyRange[x,y,z] // true

x1 = close
y1 = close - (0.6 * pipsize)
z1 = 0.5 * pipsize
a1 = CALL MyRange[x1,y1,z1] // false

x2 = close
y2 = close + (0.9 * pipsize)
z2 = 0.5 * pipsize
a2 = CALL MyRange[x2,y2,z2] // false

GRAPH a
GRAPH a1
GRAPH a2
buy at -close limit

Step-by-Step Explanation:

• Function Definition: The function `MyRange` takes three parameters: `x` (the number to check), `y` (the base number), and `z` (the range). It returns `1` if `x` is within the range `[y – z, y + z]`, otherwise it returns `0`.
• Testing the Function: The testing code sets up three scenarios to check if the current closing price (`close`) falls within various ranges defined relative to the closing price itself adjusted by a fraction of `pipsize`.
• Graphical Output: The results of the function calls (`a`, `a1`, `a2`) are plotted on the graph to visually represent whether the closing price falls within the specified ranges.
• Trading Command: The last line in the testing code (`buy at -close limit`) is a placeholder for a trading command, demonstrating how the results of the function might be used in a trading strategy.

This example is a practical demonstration of creating reusable functions in ProBuilder to simplify and organize code in trading strategies.