Re: st: cumulative average moving through time

[Daniel Lawson <dlawson1@nd.edu>]

Dear Dan,

I'm sure there is a more elegant way to do this, but how about

sort PID OB
gen calc_sum = calc
replace calc_sum = calc_sum[_n-1] + calc if (_n>1) & (PID[_n] == 
PID[_n-1])
gen cave = calc_sum / OB

Peace,
Daniel Lawson

On Oct 6, 2004, at 1:38 PM, Daniel Egan wrote:


> Hello all,
>
> I have iregularly spaced time/measurement data. I want to calculate an
> average using all prior measurements. FYI, the variable to be
> "averaged" is a dummy, so I would be looking at a percentage.
>
> a hail mary was:
>
> sort PID OB
> egen calc_sum=sum(calc[_n-_n]), by(PID)
> gen cave=calc_sum/OB
>
> which obviously does not work.
>
> My data looks like this. cave is the variable i wish I knew how to 
> create.
>
> PID	OB	dm	dm_m	calc	cave
> 1	1	1-4-2000	0	1	1
> 1	2	1-10-2000	6	0	.5
> 1	3	1-28-2000	24	0	.333
> 1	4	2-1-2000	28	1	.5
> 2	1	10-5-1998	0	1	1
> 2	2	10-8-1998	3	0	.5
> 2	3	1-22-1998	17	1	.666
> 2	4	11-5-1998	31	1	.75
>
>
>
> Thanks,
>
> Dan
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