[R] Error: evaluation nested too deeply: infinite recursion / options(expressions=)?

[David Winsemius]

On Aug 31, 2011, at 11:05 AM, Bert Gunter wrote:

>>
>> In R functions are "things" but they are not "strings" and cannot be
>> executed by just asserting a character vector element.
>
> ... But note that they can be executed by by asserting a list of
> functions component (as well as by do.call below)
>
>> x <- c(rnorm, rt, rweibull) ## this is a list of functions
>> x[[2]](10,df=5)
> [1] -1.03683857  1.20245119 -2.77762457 -0.02124206 -0.78748356   
> 1.36294023
> [7]  0.50626709 -0.37386404  0.34371389 -1.28934128

And the OP may want to also look at the examples in:

?match.arg
?match.fun

And ponder these results:

 > funlist <- list(dgamma, dnorm, dexp)
 > "dgamma" %in% funlist
[1] FALSE

 > class(funlist)
[1] "list"
 > class(funlist[1])
[1] "list"
 > class(funlist[[1]])
[1] "function"


 > match.fun("dgamma")
function (x, shape, rate = 1, scale = 1/rate, log = FALSE)
.Internal(dgamma(x, shape, scale, log))
<environment: namespace:stats>



-- 
David.
>
>
> Cheers,
> Bert
>
>
> If you want to
>> construct a 'call' from a a character, you can bridge that divide  
>> with
>> do.call:
>>
>> ?do.call
>> fn <- paste("d", "gamma", sep="")
>> do.call(fn, list(1:10, shape=1) )
>> [1] 0.36787944117 0.13533528324 0.04978706837 0.01831563889  
>> 0.00673794700
>>  [6] 0.00247875218 0.00091188197 0.00033546263 0.00012340980  
>> 0.00004539993
>>
>> --
>> David
>>

David Winsemius, MD
West Hartford, CT