[R] unexpected results

[Duncan Murdoch]

On 7/21/2006 7:36 AM, nathan wrote:
> Hi, 
> 
> I'm just learning R and am encountering some unexpected results following a
> guide on the internet. If anyone can help that would be great - I think it
> is something about the way the data has been read in!
> 
> I've read a coma delimited text data file that was saved from excel:
> 
>> jacs.data <- read.table("/Users/natha/Desktop/JACSdata2.txt", header=TRUE,
>> sep=",")
> 
> This seemed to work fine, but then I start to get unusual results that don't
> seem right:
> 
> The guide says that names(file.data) will give output like "ID" "JURIS"
> "RESCODE" , but I get ID.JURIS.RESCODE.
> 
> The guide says that file.data[5,1] will give me the data for the 5th subject
> but i get: 
> [1] 7\tACT\t\t\tSUMMONS\tACTCC321.001\tA.C.T. - MINOR THEFT (REPLACEMENT
> VALUE $2000 OR LESS)\ etc - which seems scrambled

The "\t" values are tabs.  I think your file was tab delimited, not 
comma delimited.  R thinks it has only one column, because it didn't 
fine any commas.
> 
> The guide says that file.data[var5>0] will give me the data for all subject
> who meet that condition (ie greater than 0 on var5), but I get:
> 
> Error in "[.data.frame"(jacs.data, offend > 0) : 
> 	object "offend" not found

It looks like you typed jacs.data[offend > 0].  There are two problems:

1.  You want to select rows matching the condition, so you need another 
comma, i.e.

jacs.data[offend > 0, ]

(the empty entry after the comma means "all columns").

2.  You need to have a variable named offend outside the dataframe.  The 
error message makes it look as though you don't.

If offend is a column in the dataframe, then you would use

jacs.data[jacs.data$offend > 0, ]

or

subset(jacs.data, offend > 0)

Duncan Murdoch
> can anyone help? Thanks nathan