Hi Joseph,
I tried to replicate the program that you have written
as an excercise, but I had a problem. I tried to
replicate:
forvalues i=1/2{
generate str observation'i'="An observation"
}
When I typed the closed bracket } ,Stata returned me
with an error message showing "invalid name". But
when I copied the same three lines from your email,
there was no error message. I cannot figure out the
reason. Would you please to give me a hint?
Thanks!
Yazhen
--- Joseph Coveney <[email protected]> wrote:
> Raphael Fraser wrote:
>
> I am only interested in uniqueness.
>
> I have 100 patients with ids 1-200. There are two
> observations per id.
> I would like to generate another id which I call
> bsid which ranges
> between 301-500.
>
>
--------------------------------------------------------------------------------
>
> Try something like that below. The first few lines
> just create the dataset
> that you describe. The rest create the other id
> that meets your
> specifications, and merges it with the dataset so
> that you have a so-called
> cross-walk table that you can use to decipher bsid
> in terms of the original
> patient ID.
>
> With only 200 patients, you probably won't traverse
> thel loop more than
> once; with tens of thousands or more, you might
> traverse the loop a couple
> of times. I think that the most that I've ever done
> with something similar
> is three times through, and that was to select a
> random sample of case
> report form fields for audit of a 60-page set of
> case report forms for a
> 4000-patient study. (And even there, as I recall, I
> forgot to type "double"
> after -generate-.)
>
> Joseph Coveney
>
> clear
> set more off
> tempfile tmpfil0
> set obs 200
> *
> * Creating patient dataset
> *
> generate int id = _n
> forvalues i = 1/2 {
> generate str observation`i' = "An observation"
> }
> *
> * Begin here
> *
> generate int row = _n
> sort row
> save `tmpfil0'
> local count = _N
> *
> clear
> set obs `count'
> set seed `=date("2007-01-24", "ymd")'
> generate int bsid = `count' + 100 + _n
> local quit = 1
> while (`quit') {
> generate double randu`quit' = uniform()
> sort randu`quit', stable
> capture assert randu`quit' > randu`quit'[_n-1]
> in 2/l
> if _rc `++quit'
> else continue, break
> }
> generate int row = _n
> sort row
> merge row using `tmpfil0'
> assert _merge == 3
> drop _merge row
> erase `tmpfil0'
> exit
>
> *
> * For searches and help try:
> *
> http://www.stata.com/support/faqs/res/findit.html
> * http://www.stata.com/support/statalist/faq
> * http://www.ats.ucla.edu/stat/stata/
>
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*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
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