[R] Error message: $ operator is invalid for atomic vectors

[Rui Barradas]

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.