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Re: st: Missing Values in Matrices


From   Roger Newson <[email protected]>
To   [email protected]
Subject   Re: st: Missing Values in Matrices
Date   Wed, 25 Sep 2002 15:25:42 +0100

At 08:04 25/09/02 -0500, Bill Gould wrote:

While I am very sympathetic to Nick's desire to store missing values in
matrices, I was not aware of the above and it should be treated as a bug --
something we at StataCorp need to fix -- and not a feature.

What is in fact being stored in the matrix is a NaN and, in the -generate-
follow on -- where missing values are expected -- Stata's NaN protection code
is detecting the NaN and converting it to a missing value.  Somehow that NaN
snuck through matrix assignment, however, and unfortunately, the other matrix
routines are not up to dealing with it.
What precisely is a NaN? And does it have any connection with missing values, or with the "magic number" 1e300 mentioned in -[R] tabstat-? I can't find any reference to NaNs in -[R] matrix define-.

Thanks in advance

Roger


--
Roger Newson
Lecturer in Medical Statistics
Department of Public Health Sciences
King's College London
5th Floor, Capital House
42 Weston Street
London SE1 3QD
United Kingdom

Tel: 020 7848 6648 International +44 20 7848 6648
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Email: [email protected]

Opinions expressed are those of the author, not the institution.

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