mirror of
https://github.com/zeek/zeek.git
synced 2025-10-02 14:48:21 +00:00
65 lines
No EOL
1.8 KiB
Text
65 lines
No EOL
1.8 KiB
Text
@load ./average
|
|
|
|
module Metrics;
|
|
|
|
export {
|
|
redef enum Calculation += {
|
|
## Find the variance of the values.
|
|
VARIANCE
|
|
};
|
|
|
|
redef record ResultVal += {
|
|
## For numeric data, this calculates the variance.
|
|
variance: double &log &optional;
|
|
};
|
|
}
|
|
|
|
redef record ResultVal += {
|
|
# Internal use only. Used for incrementally calculating variance.
|
|
prev_avg: double &optional;
|
|
|
|
# Internal use only. For calculating incremental variance.
|
|
var_s: double &optional;
|
|
};
|
|
|
|
hook add_to_calculation(filter: Filter, val: double, data: DataPoint, result: ResultVal) &priority=5
|
|
{
|
|
if ( VARIANCE in filter$measure )
|
|
result$prev_avg = result$average;
|
|
}
|
|
|
|
# Reduced priority since this depends on the average
|
|
hook add_to_calculation(filter: Filter, val: double, data: DataPoint, result: ResultVal) &priority=-5
|
|
{
|
|
if ( VARIANCE in filter$measure )
|
|
{
|
|
if ( ! result?$var_s )
|
|
result$var_s = 0.0;
|
|
result$var_s += (val - result$prev_avg) * (val - result$average);
|
|
result$variance = (val > 0) ? result$var_s/val : 0.0;
|
|
}
|
|
}
|
|
|
|
# Reduced priority since this depends on the average
|
|
hook plugin_merge_measurements(result: ResultVal, rv1: ResultVal, rv2: ResultVal) &priority=-5
|
|
{
|
|
if ( rv1?$var_s && rv2?$var_s )
|
|
{
|
|
local rv1_avg_sq = (rv1$average - result$average);
|
|
rv1_avg_sq = rv1_avg_sq*rv1_avg_sq;
|
|
local rv2_avg_sq = (rv2$average - result$average);
|
|
rv2_avg_sq = rv2_avg_sq*rv2_avg_sq;
|
|
result$var_s = rv1$num*(rv1$var_s/rv1$num + rv1_avg_sq) + rv2$num*(rv2$var_s/rv2$num + rv2_avg_sq);
|
|
}
|
|
else if ( rv1?$var_s )
|
|
result$var_s = rv1$var_s;
|
|
else if ( rv2?$var_s )
|
|
result$var_s = rv2$var_s;
|
|
|
|
if ( rv1?$prev_avg && rv2?$prev_avg )
|
|
result$prev_avg = ((rv1$prev_avg*rv1$num) + (rv2$prev_avg*rv2$num))/(rv1$num+rv2$num);
|
|
else if ( rv1?$prev_avg )
|
|
result$prev_avg = rv1$prev_avg;
|
|
else if ( rv2?$prev_avg )
|
|
result$prev_avg = rv2$prev_avg;
|
|
} |