Data Package Query

AIC(fit)

Date: Sat, 29 Jun 2013 05:05:28 -0800
From: jrkrideau at inbox.com
Subject: Re: [R] Data Package Query
To: y_refai at hotmail.com; rolf.turner at xtra.co.nz; jdnewmil at dcn.davis.ca.us
CC: r-help at r-project.org


I don't know what you think data(Trial) is doing but what it in fact is doing is trying to load a stored data set called Trial and it does not exist. Have a look at ?data to see what I mean.

In your program data(Trial) is redundant, well actually closer to meaningless. 

Trial is already loaded since you created it in the read statement

John Kane
Kingston ON Canada

-----Original Message-----
From: y_refai at hotmail.com
Sent: Fri, 28 Jun 2013 12:31:11 +0000
To: rolf.turner at xtra.co.nz, jdnewmil at dcn.davis.ca.us
Subject: Re: [R] Data Package Query

hello,

please advice what is wrong at the below syntax:
"Trial<-read.table("Trial.txt",header=TRUE)
Trial
save.image(file="Trial.RData")
data(Trial)
fit<-logistf(data=Trial, y~x1+x2)
"

and here is the error I get:
"Warning message:
In data(Trial) : data set ?Trial? not found
"

regards,
yasmine

Date: Fri, 28 Jun 2013 10:29:21 +1200
From: rolf.turner at xtra.co.nz
To: jdnewmil at dcn.davis.ca.us
CC: y_refai at hotmail.com; r-help at r-project.org
Subject: Re: [R] Data Package Query

On 28/06/13 04:47, Jeff Newmiller wrote:

<SNIP>

A common error by beginners (which may or may not be your problem in
this case) is to create a variable called "data". Unfortunately this
hides the function named "data" and from that time forward that R
session doesn't work when you type example code that uses the data
function.

<SNIP>

This is simply not true. I believe it *used* to be true, sometime
waaaaayyyy back,
but hasn't been true for years. The R language is much cleverer now.
If there
is a function "melvin()" somewhere on the search path and also a data
object
"melvin" (earlier on the search path) then doing

melvin(<whatever>)

will correctly call the function melvin() with no complaints. The R
language
"can tell" by the parentheses that you mean the *function* melvin and
not the
data object "melvin".

E.g.

data <- 42
require(akima)
akima
Error: object 'akima' not found
data(akima) # No error message, nor nothin'!
akima
# The data set "akima" is displayed.

All that being said it is ***BAD PRACTICE***, just in terms of
comprehensibility
and avoiding confusion, to give a data set set the same name as a
function
(either built in, or one of your own).

fortune("dog")

is relevant.

cheers,

Rolf Turner

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