[R] reading csv-data

[Spencer Graves]

	  I've struggled with this myself in the past.  I've recently started 
using the following:

File <- "pair.txt"
# File name with path if different from getwd()
readLines(File, n=9)

	  The function	"readLines" reads the first n lines as n individual 
character strings.  From this, you can identify extra headers, the 
separate characters, etc.  Then I can do something like the following:

plot(count.fields(File, sep="\t"))

	  The function "count.fields" also has arguments to specify a number of 
lines to skip before it starts to process the file, which can be helpful 
with multiple headers.  After "count.fields" produces a constant result 
consistent with what I want, then I'm ready to use "read.table" or one 
of its variants like read.csv2.

	  hope this helps.
	  spencer graves

Don MacQueen wrote:

> In my experience, this has always been due to the presence of 
> non-numeric values in the input.
> 
> In the example you show, it is not obvious that there is any. I would 
> start by first inspecting the input file very carefully, using a text 
> editor outside of R. Since your example appears to have only one 
> column of data, you could try reading it with the scan() function. 
> This might produce additional information that would help you 
> identify any non-numeric data. Using count.fields() on the data file 
> might reveal something.
> 
> If "Mean1" is an element of "data", then simply typing "Mean1" at the 
> prompt should produce a "not found" message. Yet Mean1 was found. 
> Have you omitted something in your email, or is there another object 
> named "Mean1"?
> 
> -Don
> 
> At 4:50 PM +0300 6/17/05, Johanna Sundvik wrote:
> 
>>Hi!
>>
>>I have had this problem for a long time. I have tried to study the manuals and
>>search the mailing lists, but I can not solve this. I think there 
>>has to be one
>>simple solution to this, but I just can not find it.
>>
>>I have saved the data in excel (csv-format). Then I read the data in R e.g.
>>
>>
>>>data <- read.csv2("example.csv", header=TRUE)
>>
>>I look the data and it looks ok. E.g
>>
>>
>>>data
>>
>>     Mean1  
>>1   4.4332 
>>2   8.5113 
>>3  35.1624
>>4   9.1693
>>5    2.974
>>6  65.1578
>>7  43.2241
>>8   3.1278
>>9   5.3364
>>10  3.9767
>>
>>However, this "Mean1" is categorical when it should be real numbers.
>>
>>
>>> Mean1
>>
>>[1] 4.4332  8.5113  35.1624 9.1693  2.974   65.1578 43.2241 3.1278  5.3364
>>Levels: 2.974 3.1278 35.1624 4.4332 43.2241 5.3364 65.1578 8.5113 9.1693
>>
>>Why R does not understand that this should be real numbers? What am I doing
>>wrong here? Thanks for your help.
>>
>>Regards,
>>Johanna Sundvik
>>
>>______________________________________________
>>R-help at 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
> 
> 
>