Not so. If you can analyse the data, you can also restructure them!
Sorry, but your answer is still ambiguous to me as you didn't answer my
question. I offered a choice of two wordings. You wrote your own.
This may be what you want:
Say items go -item1- to -item200-.
gen within60 = 0
qui forval i = 1/200 {
replace within60 = within60 + 1 if time`i' > 0 & time`i' <= 60
}
Nick
[email protected]
Amanda Botticello
I want to calculate how many items each subject completed within 60
seconds. And I can't do anything about the data structure,
unfortunately.
>>> "Nick Cox" <[email protected]> 11/9/2008 1:14 PM >>>
You've lost me. I don't understand how your data structure copes with
time spent on failed tasks.
Please be clear: Do you want to cumulate times and see how many tasks in
total were completed within a total of 60 seconds, as implied by your
original question, or do you just want to count how many tasks were
individually completed within 60 seconds?
Incidentally, I think you would be better off reshaping this to long.
Nick
[email protected]
Amanda Botticello
The data is more like this:
id item1 time1 item2 time2 itmem3 time3
1 1 2 1 3 1 2
2 1 5 0 0 0 0
3 1 3 1 3 1 5
The variable "item" is coded 0,1, where 1 indicates the item was
completed
Time is recorded in number of seconds to complete. If they didn't
complete an item, the time is 0
>>> "Nick Cox" <[email protected]> 11/9/2008 12:59 PM >>>
Still not very clear to me, but I guess something like this
task1 task2 task3 task4 task5
20 10 20 5 10
5 10 15 30 2
100 2 3 3 4
So that the three individuals above had completed 4, 4, 0 tasks in the
first 60 seconds.
How many within 60 seconds?
gen cumul = 0
gen within60 = 0
qui forval i = 1/5 {
replace cumul = cumul + task`i'
replace within60 = `i' if cumul <= 60
}
Nick
[email protected]
Amanda Botticello PhD, MPH
IT's a "wide" dataset...subjects completed up to 200 items in a task,
and we recorded the number of seconds it took to complete each item. I
can create a sum of the total number of items completed and total time;
now I want to find out how many items each individual completed in 60,
90, and 120 seconds. Does that help?
>>> "Martin Weiss" <[email protected]> 11/9/2008 11:00 AM >>>
Well, if you want the running sum, look at -help sum()-. But maybe you
could
give us a peek at your data structure, that would assist in answering
your
question...
"Amanda Botticello" <[email protected]>
>I have a dataset of test items and the time (in seconds)to complete
each
>item. I need to create a variable that sums the time variables up to a
>certain number -- i.e., 60, 90, 120 seconds. Is there a way I can use
the
>egen newvar = rowtot (time*) command to count up to 60 seconds, etc?
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