colClasses does not cause read.table to coerce to numeric; anymore?
On Dec 14, 2013, at 7:53 AM, Uwe Ligges wrote:
David, how should R interpret "110+"? It cannot be numeric, perhaps you have not recognized the "+" there?
I specifically included the fragment ofthe much longer file that was throwing the error. If this behavior doesn't appear flawed to you, Uwe, then am apparently under the misapprehension that it in the past it would have been coerced to NA.
David.
> Uwe
>
>
>
>
> On 14.12.2013 01:35, David Winsemius wrote:
>>
>> I thought that setting colClasses to numeric would coerce errant data to NA. Instead read.table is throwing
>> errors. This is not what I remember from prior experience with read.table and it is not how I read the help page as promising:
>>
>> BE<-
>> c(" 1841 96 42.26 31.50 73.75 ",
>> " 1841 97 29.56 20.78 50.34 ",
>> " 1841 98 18.71 10.59 29.30 ",
>> " 1841 99 10.48 6.23 16.71 ",
>> " 1841 100 6.14 4.23 10.37 ",
>> " 1841 101 3.31 2.06 5.38 ",
>> " 1841 102 1.50 0.83 2.34 ",
>> " 1841 103 0.33 0.05 0.38 ",
>> " 1841 104 0.00 0.00 0.00 ",
>> " 1841 105 0.00 0.00 0.00 ",
>> " 1841 106 0.00 0.00 0.00 ",
>> " 1841 107 0.00 0.00 0.00 ",
>> " 1841 108 0.00 0.00 0.00 ",
>> " 1841 109 0.00 0.00 0.00 ",
>> " 1841 110+ 0.00 0.00 0.00 ",
>> " 1842 0 60290.60 62238.19 122528.79 ",
>> " 1842 1 54893.31 55849.06 110742.37 ",
>> " 1842 2 51991.87 53033.62 105025.49 ",
>> " 1842 3 49697.90 50789.01 100486.91 ",
>> " 1842 4 47598.24 48414.78 96013.02 ",
>> " 1842 5 46202.38 47106.34 93308.72"
>> )
>> #-----------
>> BELe<-read.table(text=BE,
>> header=FALSE, colClasses="numeric", as.is=TRUE)
>> Error in scan(file, what, nmax, sep, dec, quote, skip, nlines, na.strings, :
>> scan() expected 'a real', got '110+'
>>
>> I originally got this when reading from a file, but the error is from scan(). Was this an unfortunate side-effect of adding the `text` argument to read.table? It does still persist when the character string is pass through textConnection tot he file argument:
>>
>> BELe<-read.table(file=textConnection(BE),
>> header=FALSE, colClasses="numeric")
>> Error in scan(file, what, nmax, sep, dec, quote, skip, nlines, na.strings, :
>> scan() expected 'a real', got '110+'
>>
>> My memory was that such coercion was effective in past years.
>>
David Winsemius
Alameda, CA, USA