I though that change in NEWS re: type.convert referenced the fact that numbers
which were longer than could be represented accurately within the constraints
of class numeric were now being read in as characters which would give you the
option to later convert with one of the bignum packages. Your error seems to
relate to decimal values being enclosed within quotes not being read in with
coercion. That's a different problem, I believe.
> read.table(text="'a' '1234'", colClasses=c('character', 'numeric'))
Error in scan(file, what, nmax, sep, dec, quote, skip, nlines, na.strings, :
scan() expected 'a real', got ''1234''
So was able to reproduce your problem fairly easily, and solve it by defining a
class and a coercion method to numeric and then using as an arcument to
colClasses.
> setClass('mycharnum', representation=list('character') )
> ?setClass
> ?as
> setAs('character', 'mycharnum' , function(from) as.numeric( from) )
>
> read.table(text="'a' '1234'", colClasses=c('character', 'mycharnum'))
V1 V2
1 a 1234
> str( read.table(text="'a' '1234'", colClasses=c('character', 'mycharnum')) )
'data.frame': 1 obs. of 2 variables:
$ V1: chr "a"
$ V2: num 1234
I'm not really sure that the representation argument is meaningful in the
setClass call. I tried with bot character and numeric and go t the same output
on this limited testing method.
--
David.
On Apr 30, 2014, at 1:20 PM, Bos, Roger wrote:
> Dear R-help,
>
> I recently upgraded to R 3.1 patched and code that ran fine previously and
> now giving a lot of errors because the data is coming in as strings instead
> of numeric. I can fix my code to wrapping each item I want to use with
> as.numeric(), but that seems very inefficient.
>
> I looked at the change list for R 3.1 and I see the first item is a change in
> type.convert() that seems to be causing me grief. The suggestion is to use
> colClasses, but when I try to do so I get an error regarding the quotes
> again...
>
>> ann1 <- read.table(driveletter %+% "/snap/ann/snap_fyr_ann1_" %+% i
>> %+% ".txt", header=TRUE, quote="", as.is=TRUE, colClasses='numeric')
> Error in scan(file, what, nmax, sep, dec, quote, skip, nlines, na.strings, :
> scan() expected 'a real', got '"1033.7"'
>
> Does anyone have any suggestions?
>
>
> CHANGES IN R 3.1.0:
> NEW FEATURES
>
>
> type.convert() (and hence by default read.table()) returns a character vector
> or factor when representing a numeric input as a double would lose accuracy.
> Similarly for complex inputs.
> If a file contains numeric data with unrepresentable numbers of decimal
> places that are intended to be read as numeric, specify colClasses in
> read.table() to be"numeric".
>
>
> ***************************************************************
> This message is for the named person's use only. It ma...{{dropped:20}}
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