[R] 'Unexpected numeric constant'

[Berend Hasselman]

On 19-03-2012, at 17:39, HJ YAN wrote:

> Dear R-help,
> 
> I am trying to rename the variables in a dataframe, called 'T1A' here.
> Seems renaming was successful, but when I call one of the variable I got
> error message and I wanted to know why.
> 
> 
> The data frame contains 365 rows and 49 columns. I would like to name the
> first column `DATE` and the others T0.5, T1, T1.5,...,T24 (as this is a set
> of data collected every half hour for a whole year).
> 
> Original data is saved as csv file and column 2-49 are named in format
> '00:30,01:00,01:30,...,23:30,00:00'. When I read them into R by using
> read.csv, the column names are changed automatically as 'X0.30.00,
> X1.00.00,...,X23.30.00,X0.00.00' , which dont look great (i mean I would
> prefer it in a format as 'hh:mm', NOT using 'dot' between numbers that used
> to indicate time, but I have not found a solution...). So I decided to use
> a simplified version as above, e.g. T0.5, T1, T1.5,...,T24 and my code is:
> 
> 
> TIME<-paste(rep("T",48),as.character(seq(0.5,24,by=0.5)))
> names(T1A)<-c("DATE",TIME)
> 
>> class(T1A$T0.5)  ## without a space between 'T' and '0.5'
> [1] "NULL"
>> class(T1A$T 0.5)  ## with a space between 'T' and '0.5'
> Error: unexpected numeric constant in "class(T1A$T 0.5"
> 
> 
> I also tried the code below, but got same error message...
> 
> TIME<-paste(rep("T",48),seq(0.5,24,by=0.5))
> names(T1A)<-c("DATE",TIME)
> 
> 
> However, if I do not change the columns' name then everything works
> fine, e.g. I can call the variables with no problem.
> 
> class(T1A$X00.30.00)
> [1] "numeric"
> 
> Any thoughts??
> 

Have you done ?paste
The default separator character is a singe space.

Use paste(....., sep="")

Berend