R-alpha: v0.10

Jim Lindsey (jlindsey@luc.ac.be)
Wed, 28 Aug 1996 10:04:47 +0200 (MET DST)

From: Jim Lindsey <jlindsey@luc.ac.be>
Message-Id: <9608280804.AA09721@alpha.luc.ac.be>
Subject: R-alpha: v0.10
To: r-testers@stat.math.ethz.ch
Date: Wed, 28 Aug 1996 10:04:47 +0200 (MET DST)

Here are a few minor problems with 0.10:
1. an empty directory called lib must be created in src for the make to work
2. in main/optimize.c, in the call to fdhess, the last argument should be
    tp instead of &tp (tp is already a pointer)
3. minimize does not give an error (message or code) when the Hessian is not
    positive definite (I guess Ross will have to fix this one).

My test suite for optimization now runs about 12% slower (2 min 15 sec
against 2 min before) than under Fortran (Linux with f2c) but it looks
like most of the problem is because, for some reason, it is not
finding the optimum a lot more often and is producing a lot more NAs.
The suite uses the random number generator a lot so is never twice the
same. I used three trials with each.

I have a function called gnlr that does nonlinear regression both for
the mean and for the shape parameter of most common distributions
(including Student, Laplace, ...) censored or not (used in the tests
above). It does what lm, glm, nlr, and survreg do in S and much
more. Now that optimization is generally available, what is the best way
to distribute it, Ross?

For those who received a copy of my R programs for my Introductory Statistics
book, we have discovered a few minor errors (mainly a couple of mistyped
data values). Let me know if your want a new copy. We also have a ps file
with a first draft of an instructor's manual if anyone is interested.

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