Error message: $ operator is invalid for atomic vectors

Hi Rui,

Thanks.? It was my fault.? I had both of these saved (read.table (), data.frame(read.table()).? I think I accidentally pasted the second one, and got the error.? 


A.K.



----- Original Message -----
From: Rui Barradas <ruipbarradas at sapo.pt>
To: arun <smartpink111 at yahoo.com>
Cc: r-help <r-help at r-project.org>
Sent: Wednesday, August 1, 2012 9:41 AM
Subject: Re: Error message: $ operator is invalid for atomic vectors

Hello,

Because there's a bug in the way I read the data: data.matrix is not 
well used here, it transforms all variables in character vectors and may 
cause problems such as

"9" < "10"

[1] FALSE

"9" > "10"

[1] TRUE

It was David Winsemius that pointed this out.
As a side effect, data.matrix returns a matrix so '$' is invalid.
Use read.table and both codes are equivalent.

Rui Barradas

Em 01-08-2012 14:28, arun escreveu:

HI,

The code was working perfectly fine yesterday and today, until half an hour ago.? Couldn't find any problems in the code. Still, I am getting error message.

myMatrix <- data.matrix(read.table(text="
Name? ? ? ? ? ? Age
ANTONY? ? ? ? 27
IMRAN? ? ? ? ? 30
RAJ? ? ? ? ? ? ? ? ? 22
NAHAS? ? ? ? ? 32
GEO? ? ? ? ? ? ? ? 42
", header=TRUE))

MinMaxArray? <- data.frame(MIN = 25,MAX=35)
myMatrix[myMatrix$Age<=MinMaxArray$MAX & myMatrix$Age>=MinMaxArray$MIN,]
#Error in myMatrix$Age : $ operator is invalid for atomic vectors


#Then, I tried Rui's code;
?  inx <- MinMaxArray[[ "MIN" ]] <= myMatrix[, "Age"] & myMatrix[, "Age"]<= MinMaxArray[[ "MAX" ]]
?  myMatrix[ inx , ]
? ? ?  Name Age
[1,]? ? 1? 27
[2,]? ? 3? 30
[3,]? ? 4? 32
#Previously, this was also working fine.

Not sure what is happening.

A.K.