[R] Plot error

[James Platt]

Hi both,

Sorry my mistake I was trying to make a graph from another file I  
called seq, I decided to use test as an example, but mixed up the two.

I have got this to work now thanks.

after doing this:

> #Assign columns to variables 'x' and 'y'
> x <- test[ , "value_1"]
> y <- test[ , "value_2"]
>
> #plot
> plot(x, y)

cheers,

James

On 17 Jul 2010, at 16:07, Joshua Wiley wrote:

> Hi James,
>
> I believe the issue has to do with the values you assigned to 'x' and
> 'y'.  You call the function c() on seq["value_1"], but you assigned
> your data not to 'seq' but to 'test'.  You need to use the variable
> name that you assigned your data to (as a side note seq() is a
> function, so you should probably avoid using that as name to store
> data anyways).  Also you have data in a variable 'test' that has both
> rows and columns, so the preferred way to access it is
> variablename[rowname/number , columnname/number].  In your case that
> would be test[ , "value_1"].  I left the space before the comma blank
> to indicate include all rows.  It does technically work in this case
> to simply write test["value_1"] but this is prone to error in other
> situations.  This is my best guess as to what you want to do:
>
> #Read in Data
> #(just to make sure were on the same page)
> test <- structure(list(name = structure(c(2L, 1L, 3L),
> .Label = c("ben", "bill", "jane"), class = "factor"),
> value_1 = 1:3, value_2 = c(4L, 2L, 1L)),
> .Names = c("name", "value_1", "value_2"),
> class = "data.frame", row.names = c(NA, -3L))
>
> test # print so we can look at it
>
> #Assign columns to variables 'x' and 'y'
> x <- test[ , "value_1"]
> y <- test[ , "value_2"]
>
> #plot
> plot(x, y)
>
> #Or using data directly
> plot(test[ , "value_1"], test[ , "value_2"])
>
> Cheers,
>
> Josh
>
> On Sat, Jul 17, 2010 at 7:50 AM, James Platt <james-platt at hotmail.co.uk 
> > wrote:
>> Hi guys,
>>
>> I am a newbie to R, so apologies in advance.
>>
>> I created this simple table in excel, saved in tab delimited .txt:
>>
>> name value_1 value_2
>> 1 bill       1            4
>> 2 ben      2           2
>> 3 jane     3           1
>>
>>
>>> test <-read.table("\path\to\file", sep="\t", header=TRUE)
>>
>>> x <-c(seq["value_1"])
>>> y <-c(seq["value_2"])
>>
>>> plot(x,y)
>>
>> and i get this error
>>
>> Error in xy.coords(x, y, xlabel, ylabel, log) :
>>  (list) object cannot be coerced to type 'double'
>>
>> What does this mean and how do i fix it?
>>
>> Thanks for the help, James
>>
>> ______________________________________________
>> R-help at r-project.org 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.
>>
>
>
>
> -- 
> Joshua Wiley
> Ph.D. Student, Health Psychology
> University of California, Los Angeles
> http://www.joshuawiley.com/
>