[R] [External] Get a result but an error message as well ?

[varin sacha]

Hi Rui, Richard and other,

Many thanks for your responses that solve my problem.

Best,
SV







Le mercredi 20 mai 2020 à 09:09:49 UTC+2, Rui Barradas <ruipbarradas using sapo.pt> a écrit : 





Hello,

I get an error but when running colnames(), not mean().
Notes:

1. I have changed the way the residuals are extracted, if there is a 
function resid(), the recommended practice is to use it.
2. c("MSE_OLS") and "MSE_OLS" are the identical() objects. Likewise, to 
return( c(MSE_OLS) ) is to have only MSE_OLS as the last function line. 
I find the latter clearer.


my.experiment <- function() {
  OLS <- lm(a ~ b + d)
  #MSE_OLS <- mean(OLS$residuals^2)
  MSE_OLS <- mean(resid(OLS)^2)
  MSE_OLS
}

my.data <- replicate( 500, my.experiment() )

class(my.data)  # it's a vector, not a matrix
#[1] "numeric"

colnames(my.data) <- "MSE_OLS"
#Error in `colnames<-`(`*tmp*`, value = "MSE_OLS") :
#  attempt to set 'colnames' on an object with less than two dimensions

mean(my.data)
#[1] 105.6951


Hope this helps,

Rui Barradas

Às 22:25 de 19/05/20, varin sacha escreveu:
> Hi Rui,
> 
> If I don't transpose t() the output of the replicate (my R code here below) I still get an error message !!
> 
> ########################################
> a=c(2,4,3,4,6,5,3,1,2,3,4,3,4,5,65)
> b=c(23,45,32,12,23,43,56,44,33,11,12,54,23,34,54)
> d=c(9,4,5,3,2,1,3,4,5,6,4,9,10,11,18)
> 
> my.experiment <- function() {
> 
> OLS <- lm( a ~ b+d )
> 
> MSE_OLS<-mean(OLS$residuals^2)
> 
> return( c(MSE_OLS) )
> }
> 
> my.data = replicate( 500, my.experiment() )
> colnames(my.data) <- c("MSE_OLS")
> mean(my.data)
> ########################################
> 
> 
> 
> 
> 
> 
> Le mardi 19 mai 2020 à 23:14:21 UTC+2, Rui Barradas <ruipbarradas using sapo.pt> a écrit :
> 
> 
> 
> 
> 
> Hello,
> 
> Inline.
> 
> Às 21:38 de 19/05/20, varin sacha via R-help escreveu:
>>
>> Hi Richard,
>>
>> Thanks for your response.
>> However, how can I correct my R code knowing that I want, as a result, only one value : the mean of the 500 MSE_OLS values ?
> 
> Just don't transpose the output of replicate?
> 
> Hope this helps,
> 
> Rui Barradas
> 
>>
>>
>>
>>
>>
>>
>>
>> Le mardi 19 mai 2020 à 21:59:07 UTC+2, Richard M. Heiberger <rmh using temple.edu> a écrit :
>>
>>
>>
>>
>>
>>> dim(my.data)
>> [1]   1 500
>>
>> you have a matrix with a single row and 500 columns.
>> you gave a name to only the first column.
>>
>> Look at the result of replicate().  it is a vector.  You transposed it into a one-row matrix.
>>
>>>     tmp <- replicate( 500, my.experiment() )
>>> dim(tmp)
>> NULL
>>> length(tmp)
>> [1] 500
>>> dim(t(tmp))
>> [1]   1 500
>>
>>
>> On Tue, May 19, 2020 at 3:51 PM varin sacha via R-help <r-help using r-project.org> wrote:
>>> Dear R-experts,
>>>
>>> Here is my R code, I get a result but I also get an error message so I doubt I can trust the result I get.
>>> What is going wrong ? Many thanks.
>>>
>>> ########################################
>>> a<-c(2,4,3,4,6,5,3,1,2,3,4,3,4,5,65)
>>> b<-c(23,45,32,12,23,43,56,44,33,11,12,54,23,34,54)
>>> d<-c(9,4,5,3,2,1,3,4,5,6,4,9,10,11,18)
>>>
>>> my.experiment <- function( ) {
>>>
>>> OLS <- lm( a ~ b+d )
>>> MSE_OLS<-mean(OLS$residuals^2)
>>> return( c(MSE_OLS) )
>>> }
>>>
>>> my.data = t(replicate( 500, my.experiment() ))
>>> colnames(my.data) <- c("MSE_OLS")
>>> mean(my.data)
>>> ########################################
>>>    
>>>
>>> ______________________________________________
>>> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
>>> 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.
>>>
>>
>> ______________________________________________
>> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> 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.
>>