[R] problem with optim: (list) object cannot be coerced to 'double'

[Uwe Ligges]

Zebouni, Stephane (Exchange) wrote:

> Hi,
> 
>  
> 
> I am trying to use optim to solve a heavy calibration problem. I supply
> the parameters in vector form. But before entering my target 
> 
>  
> 
> The call is simply:
> 
>  
> 
> optim(par = parameters, fn = SumLSQ, method = "Nelder-Mead")
> 
>  
> 
> the function SumLSQ is simply:
> 
>  
> 
> SumLSQ<-function(parameters, data = timeseries){
> 
>  
> 
> print("sumLSQ")
> 
>       
> 
>  
> 
>       nbseries = dim(timeseries)[2]/3
> 
>  
> 
>       SumLSQ = 0
> 
>       
> 
>       for (i in (1:nbseries)){
> 
>             SumLSQ = SumLSQ +
> LSQ(parameters,timeseries[,((i-1)*3+1):(i*3)])
> 
>       }
> 
>  
> 
> }
> 
>  
> 
> I actually never enter the objective function SumLSQ. I always receive
> the error:
> 
>  
> 
> (list) object cannot be coerced to 'double'
> 
>  
> 
> And I really don't know where it comes from. II thought it was the
> format of "par" argument but I think it is correct to supply a numerical
> vector  ...

Yes, it is. Please type
   str(parameters)
an tell us the result.

Uwe Ligges



> 
>  
> 
> Thnaks a lot for any help!
> 
>  
> 
> Stephane
> 
>  
> 
>  
> 
> 
> 
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