[R] optimization in for loop

[David Winsemius]

On Jun 29, 2011, at 2:31 PM, siriustar wrote:

> Hi, dear R help
> I am trying to use optim inside a for loop:
>
> ##For example. a: intial guess.  b: result.  f: function to be  
> minimized
> for (i in 1:10) {
>  b[i] <- optim(a[i], f)}
>
> However, some intial values cause error in optim function (e.g. "  
> system is
> computationally singular..."). Then the for loop stops and won't try  
> the
> following initial guesses.

If you want to work around errors, you need to catch them and provide  
alternative:

?try


>
> What can I do if I want the for loop procedure to finish all the  
> initial
> guesses? I know this may be a stupid question.. but I am not familar  
> with R
> optim. So thankyou very much for any help..
>
> Sirius
>
> --
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>
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David Winsemius, MD
West Hartford, CT