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Re: st: predicting height by age for each individual
From
Maarten Buis <[email protected]>
To
[email protected]
Subject
Re: st: predicting height by age for each individual
Date
Thu, 30 Jan 2014 16:47:22 +0100
I have two comments:
As a father I can tell you that height does not change linearly with
age in that period. You might want to look at -fp- in order to create
a reasonable model.
Imangine what happens in your code when you have three persons. Your
first regression will fill in for person 2 and 3, your second
regression will be used to fill in 1 and 3, but wait.. you already
filled in for person 3. What do you want to do in that case?
-- Maarten
On Thu, Jan 30, 2014 at 4:26 PM, Y.R.E. Retamal <[email protected]> wrote:
> Dear STATA users
>
> I am studying growth and development in children from 0 to 3 years old. I am
> using a longitudinal database of children where height and weight were
> measured from birth to three years old (1600 children).
> I would like to predict height of each child from birth until three years
> old for each six months (birth, 6, 12, 18, ..., 36 month), after running a
> linear regression of height by age for each child, not all at the same time.
> For example, I have the following database:
>
> id month height
> 1 0 59
> 1 6 68
> 1 12 70
> 1 18 74
> 1 24 81
> 1 30 86
> 1 36 94
> 2 0 50
> 2 6 55
> 2 12 74
> 2 18 80
> 2 24 82
> 2 30 87
> 2 36 95
>
>
> I could do:
> reg height month if id==1
> predict xb if id!=1
> reg height month if id==2
> predict xb if id!=2
>
> and so...
>
> But, I have 1600 children, therefore I should write the same commands per
> each child (1600 times), something truly inefficient and tedious. There is a
> command or program to run the same commands, but automatically?
>
>
> Any help would be very appreciated.
> Rodrigo
>
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--
---------------------------------
Maarten L. Buis
WZB
Reichpietschufer 50
10785 Berlin
Germany
http://www.maartenbuis.nl
---------------------------------
*
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