Stata The Stata listserver
[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

Re: st: Missing Values in Matrices


From   Roger Newson <roger.newson@kcl.ac.uk>
To   statalist@hsphsun2.harvard.edu
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
Fax: 020 7848 6620 International +44 20 7848 6620
or 020 7848 6605 International +44 20 7848 6605
Email: roger.newson@kcl.ac.uk

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

*
* 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/




© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index