Inbuilt Aggregate Functions

Following are the supported inbuilt aggregate functions of Siddhi.

sum

<long|double> sum(<int|long|double|float> arg)

• Extension Type: Aggregate Function 
• Description: Sums all the events.
• Parameter: arg: The value that need to be summed.
• Return Type: Returns long if the input parameter type is int or long and Returns double if the input parameter type is float or double.
• Examples: sum(20) returns sum of 20s as a long value for each event arrival and expiry. sum(temp) returns the sum of all temp attributes based on each event arrival and expiry.

avg

<double> avg(<int|long|double|float> arg)

• Extension Type: Aggregate Function
• Description: Calculates the average for all the events.
• Parameter: arg: The value that need to be averaged.
• Return Type: Returns calculated average value as a double.
• Examples: avg(temp) returns the average temp value for all the events based on their arrival and expiry.

max

<int|long|double|float> max(<int|long|double|float> arg)

• Extension Type: Aggregate Function
• Description: Returns the max value for all the events.
• Parameter: arg: The value that need to be compared to find the max value.
• Return Type: Returns max value in same type as the input.
• Examples: max(temp) returns the maximum temp value recorded for all the events based on their arrival and expiry.

min

<int|long|double|float> min(<int|long|double|float> arg)

• Extension Type: Aggregate Function
• Description: Returns the min value for all the events.
• Parameter: arg: The value that need to be compared to find the min value.
• Return Type: Returns min value in same type as the input.
• Examples: min(temp) returns the minimum temp value recorded for all the events based on their arrival and expiry.

count

<long> count()

• Extension Type: Aggregate Function
• Description: Returns the count of all the events.
• Return Type: Returns event count as a long.
• Examples: count() will return the count of all the events.

stddev

<double> stddev(<int|long|double|float> arg)

• Extension Type: Aggregate Function
• Description: Returns the calculated standard deviation for all the events.
• Parameter: arg: The value that should be used in calculating the standard deviation.
• Return Type: Returns calculated standard deviation value as a double.
• Examples: stddev(temp) returns the calculated standard deviation of temp, for all the events based on their arrival and expiry.