The challenge in awk is to recognize a time range to correspond with a measurement.
Normally you'd like to use something like PERL's timelocal() function to map to seconds and chop into a range.
With that it would be easy to see with integer math whether a new record is a certain (5) number of seconds beyond the range or not.
We can not 'subtract' the string time to see whether 5 seconds have elapsed.
If we may assume that the records are nicely in order, then we may have a string workaround. For each input line we can find the string which corresponds to the begin of a range.
Now remember the current range.
If a record no longer has the same range (doesn't matter whether it is the same day or hour still!) then report what was accumulated so far.
And of course report the last range after the last record read.
For example, check out a potential solution below. (Remove debug information for production version).
$ cat x.awk
function range_report() {
printf ("-- %s %d %5.2f\n", old_range, range_count, range_value/range_count);
}
/^[0-9]+\// { # Starts with a date?
split ( $2, x, ":" ); # hours and minutes
range = sprintf ("%s %02d:%02d", $1, x[1], 5*int(x[2]/5))
# print range, x[1], x[2], $0;
if (range == old_range) {
range_count++;
range_value += $3;
} else {
if (range_count) range_report();
range_count = 1;
range_value = $3;
old_range = range;
}
}
END {range_report()}
$ cat x
10/27/2007 00:00 13.82
10/27/2007 00:01 20.95
10/27/2007 00:02 10.79
10/27/2007 00:03 11.78
10/27/2007 00:04 11.77
10/27/2007 00:05 9.96
10/27/2007 00:06 12.69
10/27/2007 00:07 18.94
10/27/2007 08:28 17.91
10/27/2007 08:29 18.00
10/28/2006 00:01 10.79
10/28/2006 00:03 11.78
10/28/2006 00:04 11.77
10/30/2006 00:08 9.96
10/30/2006 00:09 12.69
10/30/2006 00:10 18.94
$ awk -f x.awk x
-- 10/27/2007 00:00 5 13.82
-- 10/27/2007 00:05 3 13.86
-- 10/27/2007 08:25 2 17.95
-- 10/28/2006 00:00 3 11.45
-- 10/30/2006 00:05 2 11.32
-- 10/30/2006 00:10 1 18.94
Hope this helps some,
Hein van den Heuvel (at gmail dot com)
HvdH Performance Consulting
