Mailing List Archive: 49091 messages

# Average of times

### [1/4] from: ml::sproingle::com at: 3-May-2004 9:30

I have a series of times which represents session durations of users. They are in the format dd:hh:mm What I want to figure out is how long the average session takes. Do I have to parse out the days and hours into minutes and then work out the average that way and then convert the result back into dd:hh:mm or does someone know of a better way? Stuart

### [2/4] from: antonr:lexicon at: 4-May-2004 0:23

Let b be a block containing your session times.
>> b: [1:00:21 2:00 3:30]
== [1:00:21 2:00 3:30]
>> t: 0:0 ; total
== 0:00
>> foreach time b [t: t + time]
== 6:30:21
>> t / length? b
== 2:10:07 Anton.

### [3/4] from: SunandaDH:aol at: 3-May-2004 14:47

Anton:
> Let b be a block containing your session times.
That works if the durations are hours:minutes:seconds -- you are using REBOL's standard date arithmetic. But, if I read Stuart's question right, he has days:hours:minutes. They don't add right in the same way: 1:12:00 + 1:12:00 should be 3:00:00 in his example (1 day & 12 hours, twice) In REBOL, 1:12:00 + 1:12:00 = 2:24 Here's a couple of functions that misuse the date format to treat it as d:h:m for addition. The result is in hours:minutes -- you'll need a bit more arithmetic to convert that to days:hours:minutes -- after dividing to get the average, that is. make-hm: func [d1 [time!] ][ return to-time join d1/minute [":" d1/second ":00"] ] add-dhm: func [d1 [time!] d2 [time!] ][ return (make-hm d1) + (make-hm d2) + (24 * 3600 * to-time (d1/hour + d2/hour)) ] ;; examples: add-dhm 1:12:0 1:12:0 ;; 1.5 days + 1.5 days == 72:00 ;; seventy-two hours = three days add-dhm 0:30:30 0:30:30 == 61:00 add-dhm 2:1:45 0:0:15 == 50:00 Sunanda. Sunanda

### [4/4] from: greggirwin:mindspring at: 3-May-2004 15:44

Hi Stuart, M> I have a series of times which represents session durations of users. M> They are in the format dd:hh:mm M> What I want to figure out is how long the average session takes. This is a good example of something that could be done many different ways in REBOL (like a lot of things :). Here's what came into my head. make-dhm-time: func [time /local ms] [ ms: time // 24:00 to time! reduce [to integer! time / 24:00 ms/hour ms/minute] ] avg-dhm-times: func [block /local result] [ result: 0:0:0 foreach t block [ result: add result to time! reduce [ t/hour * 24 + t/minute to integer! t/second ] ] make-dhm-time result / length? block ] -- Gregg