[R] How to resolve the following error: (list) object cannot be coerced to type 'double'

[Rui Barradas]

Hello,

The input must be a matrix, not a list (or its special case data.frame).

Var <- read.table(text="
   D.Prime    T.statistics
1    1.7234e-01     4.926800
2    1.4399e-01     2.892000
3    1.4626e-01     2.642800
4    3.5147e-02     1.112400
5    5.8957e-02     2.723700
", header=TRUE)

# library(Hmisc)
rc <- rcorr(as.matrix(Var), type="pearson")
# from recommended package stats
ct <- cor.test(Var$D.Prime, Var$T.statistics, method = "pearson")

rc$P
                D.Prime T.statistics
D.Prime             NA    0.1101842
T.statistics 0.1101842           NA

ct$p.value
[1] 0.1101842

To the op: you should say which library you are using. Even if Hmisc is 
a very popular one.

Hope this helps,

Rui Barradas


Em 12-09-2012 16:10, R. Michael Weylandt escreveu:
> On Wed, Sep 12, 2012 at 4:04 PM, Jason Love <jason.love1492 at gmail.com> wrote:
>> Hello,
>> I'd like to test a significance of two variables in their correlation using
>> rcorr, which gave me an error of format incompatibility.
>> Below are the lines that I typed in the R window and let me know if anyone
>> knows how to resolve this.
>>
>> Var=read.csv("03apr10ab_corr_matrix_in_overlaps.csv",header=F)
>> colnames(Var)=c("D Prime","T statistics")
>>
>>           D Prime    T statistics
>> 1    1.7234e-01     4.926800
>> 2    1.4399e-01     2.892000
>> 3    1.4626e-01     2.642800
>> 4    3.5147e-02     1.112400
>> 5    5.8957e-02     2.723700
>>
>>
>> rcorr(Var, type="pearson")
> Untested (because I'm still without respectable internet after a move)
> I believe rcorr would rather have a matrix than a data.frame(), which
> is what read.csv produces, so try
>
> Var <- as.matrix(Var)
>
> or
>
> rcorr(as.matrix(Var), type = "pearson")
>
>> Error in storage.mode(x) <- if (.R.) "double" else "single" :
>>    (list) object cannot be coerced to type 'double'
> This suggests that the input to rcorr is being converted to a double,
> which isn't a valid storage.mode change for a list (= data frame).
>
> Cheers,
> M
>
>>          [[alternative HTML version deleted]]
>>
>> ______________________________________________
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>> https://stat.ethz.ch/mailman/listinfo/r-help
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>> and provide commented, minimal, self-contained, reproducible code.
> ______________________________________________
> 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.