From rpeng@stat.ucla.edu  Tue Jan 21 23:07:03 2003
From: rpeng@stat.ucla.edu (Roger Peng)
Date: Tue Jan 21 23:07:03 2003
Subject: [Rd] Methods package is now attached by default
In-Reply-To: <Pine.LNX.4.44.0301200935370.2333-100000@gannet.stats>
Message-ID: <Pine.GSO.4.10.10301211356280.15902-100000@quetelet.stat.ucla.edu>

I was looking at the examples in the `optim' help page and I think one of
them does not quite work.  In particular, this example:

## "wild" function , global minimum at about -15.81515
fw <- function (x)
     10*sin(0.3*x)*sin(1.3*x^2) + 0.00001*x^4 + 0.2*x+80
plot(fw, -50, 50, n=1000, main = "optim() minimising `wild function'")

While it executes, I think it produces the wrong plot.  The call to plot
indicates that it should be plotted from x values of -50 to 50 but the
resulting plot goes from 0 to 50.  However, if I call

plot.function(fw, -50, 50, n = 1000, 
              main = "optim() minimising `wild function'")


then that plot appears to be correct.  I figured this had something to do
with the method dispatching on functions.

This occurs when I do a --vanilla startup.

> version
         _                           
platform i686-pc-linux-gnu           
arch     i686                        
os       linux-gnu                   
system   i686, linux-gnu             
status   Under development (unstable)
major    1                           
minor    7.0                         
year     2003                        
month    01                          
day      21                          
language R                           


-roger
_______________________________
UCLA Department of Statistics
rpeng@stat.ucla.edu
http://www.stat.ucla.edu/~rpeng



[Rd] Methods package is now attached by default
Roger Peng