lquantize

Stores the linear frequency distribution of the values of the specified expressions, sized by the specified range, in an aggregation.

void lquantize(expr, int32_t from, int32_t to [, int32_t step])

The lquantize function is an aggregation function used to display a linear value distribution. The lquantize function takes four arguments: a D expression, expr, a lower bound, from, an upper bound, to, and an optional step. Note that the default step value is 1.

Example 7-24 How to use lquantize to display the distribution of write() calls by file descriptor

syscall::write:entry
{
  @fds[execname] = lquantize(arg0, 0, 100, 1);
}

Output similar to the following might be displayed after the program exits:

 ...
  gnome-session                                     
           value  ------------- Distribution ------------- count    
              25 |                                         0        
              26 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 9        
              27 |                                         0        

  gnome-terminal                                    
           value  ------------- Distribution ------------- count    
              15 |                                         0        
              16 |@@                                       1        
              17 |                                         0        
              18 |                                         0        
              19 |                                         0        
              20 |                                         0        
              21 |@@@@@@@@                                 4        
              22 |@@                                       1        
              23 |@@                                       1        
              24 |                                         0        
              25 |                                         0        
              26 |                                         0        
              27 |                                         0        
              28 |                                         0        
              29 |@@@@@@@@@@@@@                            6        
              30 |@@@@@@@@@@@@@                            6        
              31 |                                         0        
 ...