This ProBuilder code snippet demonstrates how to calculate the median of the last ‘n’ close prices in a trading chart. The median is a valuable statistical measure that indicates the middle value of a dataset, providing insights into the central tendency of the data.

once Median=0 
if barindex>length then 
FOR X = 0 TO length-1 
M = close[X] //this example takes the median of the last 5 closes 
SmallPart = 0 
LargePart = 0 
FOR Y = 0 TO length-1 
IF close[Y] < M THEN 
SmallPart = SmallPart + 1 
ELSIF 
close[Y] > M THEN 
LargePart = LargePart + 1 
ENDIF 
IF LargePart = SmallPart AND Y = length-1 THEN 
Median = M 
BREAK 
ENDIF 
NEXT 
NEXT 
endif 
Return Median as "Median"

Explanation of the Code:

• The code initializes the Median variable to 0 and checks if the current bar index is greater than the specified length to ensure there are enough data points.
• A FOR loop iterates from 0 to length-1, setting M to each close price in this range.
• For each M, two counters, SmallPart and LargePart, are initialized to zero. These counters track the number of close prices less than and greater than M, respectively.
• Another FOR loop iterates through all close prices again to compare each with M and increments the appropriate counter based on whether the close price is less than or greater than M.
• If at the end of the inner loop (Y = length-1), SmallPart equals LargePart, it indicates that M is the median, and the loop breaks.
• The median value is then returned.

This code effectively finds the median of the last ‘n’ close prices, which can be useful for identifying the middle value in a series of trading data points, helping to understand market trends without the influence of outliers.