Re: [R] Problem with data type recognition and conversion
Hi On 31 Oct 2006 at 22:42, tom soyer wrote: Date sent: Tue, 31 Oct 2006 22:42:40 -0600 From: tom soyer [EMAIL PROTECTED] To: r-help r-help@stat.math.ethz.ch Subject:[R] Problem with data type recognition and conversion Hi, I have a CSV file with two columns; the first column is date, second column is numbers. I used read.csv() to load the file into the variable temp. Somehow, R could not recognize my numbers as double. Instead, it thinks these numbers are integer even though they all have decimal points (isn't that strange?). The problem I ran into is that if I tried to convert the numbers to double using as.double, R doesn't give me the original value; e.g. 9.92 becomes 805 (see below). temp[1,2] [1] 9.92 812 Levels: . 10.00 10.01 10.02 10.03 10.04 10.05 10.06 10.07 10.08 10.09 10.10 10.11 10.12 ... 9.99 typeof(temp[1,2]) [1] integer as.double(temp[1,2]) [1] 805 Levels always tell you it is a factor. Your csv file has an extra decimal point or something odd that forces R to convert second column to factor. You can transfer factor variable to numeric one by as.numeric(as.character(temp[,2])) however I recommend you to go through your csv file (if it is not too big) and find the problematic item. If I leave the numbers as integer, then I can't do arithmetic operations on them. Does anyone know what's going on? see ?factor HTH Petr Thanks, Tom [[alternative HTML version deleted]] __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. Petr Pikal [EMAIL PROTECTED] __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Problem with data type recognition and conversion
Your 'numbers' are in fact a factor: note what it says about 'levels',
and that one level is '.'. So very likely there was a non-number ('.') in
that column of your input file.
Please study 'An Introduction to R' and familiarize yourself with factors.
typeof() is useful for basic types, but not for classed objects such as
factors.
On Tue, 31 Oct 2006, tom soyer wrote:
Hi,
I have a CSV file with two columns; the first column is date, second column
is numbers. I used read.csv() to load the file into the variable temp.
Somehow, R could not recognize my numbers as double. Instead, it thinks
these numbers are integer even though they all have decimal points (isn't
that strange?). The problem I ran into is that if I tried to convert the
numbers to double using as.double, R doesn't give me the original value; e.g.
9.92 becomes 805 (see below).
temp[1,2]
[1] 9.92
812 Levels: . 10.00 10.01 10.02 10.03 10.04 10.05 10.06 10.07 10.08
10.09 10.10 10.11 10.12 ... 9.99
typeof(temp[1,2])
[1] integer
as.double(temp[1,2])
[1] 805
If I leave the numbers as integer, then I can't do arithmetic operations on
them. Does anyone know what's going on?
Thanks,
Tom
[[alternative HTML version deleted]]
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--
Brian D. Ripley, [EMAIL PROTECTED]
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UKFax: +44 1865 272595
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and provide commented, minimal, self-contained, reproducible code.
Re: [R] Problem with data type recognition and conversion
tom soyer wrote: Hi, I have a CSV file with two columns; the first column is date, second column is numbers. I used read.csv() to load the file into the variable temp. Somehow, R could not recognize my numbers as double. Instead, it thinks these numbers are integer even though they all have decimal points (isn't that strange?). The problem I ran into is that if I tried to convert the numbers to double using as.double, R doesn't give me the original value; e.g. 9.92 becomes 805 (see below). The data seem to have been read as a factor, probably due to the wrong delimiter being supplied or assumed. Make sure that the delimiter in the file is the one specified on the read.* function. Another thing that might mess up the input is quote characters. Jim __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Problem with data type recognition and conversion
Thanks Jim, Brian, and Petr. I found a non-number, ., in my CSV file that prevented R from reading the data correctly. Once I got rid of it, R works fine. Thanks! On 11/1/06, Jim Lemon [EMAIL PROTECTED] wrote: tom soyer wrote: Hi, I have a CSV file with two columns; the first column is date, second column is numbers. I used read.csv() to load the file into the variable temp. Somehow, R could not recognize my numbers as double. Instead, it thinks these numbers are integer even though they all have decimal points (isn't that strange?). The problem I ran into is that if I tried to convert the numbers to double using as.double, R doesn't give me the original value; e.g. 9.92 becomes 805 (see below). The data seem to have been read as a factor, probably due to the wrong delimiter being supplied or assumed. Make sure that the delimiter in the file is the one specified on the read.* function. Another thing that might mess up the input is quote characters. Jim [[alternative HTML version deleted]] __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
