The avg aggregate computes the average, or mean, value of the values in each specified dimension.

Synopsis

AFL% aggregate(array,avg(attribute)[,dimension_1,dimension_2,...]

Summary

The avg aggregate computes the average, or mean, value of the values in each specified dimension.

Rules for empty cells and NULL values.

• avg of an empty array is NULL.
• avg of an attribute dimension that contains only NULL values is  NULL.
• avg of an attribute dimension that has some non-NULL values is the average of the non-NULL values only.

Example

To find the average of the rows or columns of an array:

1. Create an array:

   AFL% create array M <v:double>[row=0:1; col=0:1];
   AFL% store(build(M,row*2+col),M); 

   
   The output is:

   {row,col} v
   {0,0} 0
   {0,1} 1
   {1,0} 2
   {1,1} 3

2. Find the average of each row:
   

   AFL% aggregate(M,avg(v),row) 

   
   The output is:
   

   {row} v_avg
   {0} 0.5
   {1} 2.5

3. Find the average of each column:

   AFL% aggregate(M,avg(v),col) 

   
   The output is:

   {row} v_avg
   {0} 1
   {1} 2