R help - Mar 2009 - Help with Wilcoxon Test

Hi
I have 2 sets of data that I want to do a Wilcoxon test on. They are of the same
dimension. One has 4 zero values and the other has 5.
> dim(SampA)
[1]  1 10
> dim(SampV)
[1]  1 10
 
I get the folowing error 

Error in wilcox.test.default(SampA, SampV, na.rm = TRUE, paired = FALSE,  : 
  'x' must be numeric



I am using the function
wilcox.test(SampA, SampV, na.rm=TRUE, paired=FALSE, conf.level=0.95)

What do you get with:

str(SampA)
str(SampV)

The error message suggests you are not giving it numeric vectors.

--  
David Winsemius
On Mar 2, 2009, at 10:59 AM, Amit Patel wrote:
> Hi
> I have 2 sets of data that I want to do a Wilcoxon test on. They are  
> of the same dimension. One has 4 zero values and the other has 5.
>> dim(SampA)
> [1]  1 10
>> dim(SampV)
> [1]  1 10
>
> I get the folowing error
>
> Error in wilcox.test.default(SampA, SampV, na.rm = TRUE, paired =  
> FALSE,  :
>  'x' must be numeric
>
>
>
> I am using the function
> wilcox.test(SampA, SampV, na.rm=TRUE, paired=FALSE, conf.level=0.95)
>
>
>
>
>
> ______________________________________________
> 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.

Hi, 

type

is(sampA)

is(sampV)

in the R-prompt. It will show you that at least one of the vectors is not a
vector of numerical values in R's sense. Then you have to convert using the
as.numeric() function, but you will have to make sure that this really gives
you the original vectors. Since your vectors are only 1x10, it's probably
easier to type them in anew.

Cheers,
Daniel


-------------------------
cuncta stricte discussurus
-------------------------

-----Urspr?ngliche Nachricht-----
Von: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] Im
Auftrag von Amit Patel
Gesendet: Monday, March 02, 2009 11:00 AM
An: r-help at r-project.org
Betreff: [R] Help with Wilcoxon Test

Hi
I have 2 sets of data that I want to do a Wilcoxon test on. They are of the
same dimension. One has 4 zero values and the other has
5.
> dim(SampA)
[1]  1 10
> dim(SampV)
[1]  1 10
 
I get the folowing error 

Error in wilcox.test.default(SampA, SampV, na.rm = TRUE, paired = FALSE,  : 
  'x' must be numeric



I am using the function
wilcox.test(SampA, SampV, na.rm=TRUE, paired=FALSE, conf.level=0.95)





______________________________________________
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.

Amit Patel wrote:
> Hi
> I have 2 sets of data that I want to do a Wilcoxon test on. They are of the
same dimension. One has 4 zero values and the other has 5.
>   
>> dim(SampA)
>>     
> [1]  1 10
>   
>> dim(SampV)
>>     
> [1]  1 10
>  
> I get the folowing error 
>
> Error in wilcox.test.default(SampA, SampV, na.rm = TRUE, paired = FALSE,  :
>   'x' must be numeric
>
>
>
> I am using the function
> wilcox.test(SampA, SampV, na.rm=TRUE, paired=FALSE, conf.level=0.95)
>   
Hi Amit,
This is probably due to the fact that SampA is not numeric (SampB may be 
the same). When you say "zero values", I suspect you may mean NAs, and
SampA and SampB are read in from a data file of some sort. It's quite 
common for users to assume that an empty field (or even a space or a 
period ".") will be read as NA. If this sounds like it may be the 
problem, check the function that you are using to read in the data for 
an na.strings argument, and see if it is what you think it is. If it 
isn't, any column of a resulting data frame will usually come in as a 
factor.

Jim