[R] defining a function using strings

[Dimitris Rizopoulos]

try this:

library(orthopolynom)
l <- legendre.polynomials(4)
fun.l <- lapply(l, as.function)

fun.l[[3]](1:3)


I hope it helps.

Best,
Dimitris


Chernomoretz Ariel wrote:
> Hi All,
> I need to evaluate a series expansion using Legendre polynomials.
> Using the 'orthopolinom' package I can get a list of the first n
> Legendre polynomials as character strings.
> 
>> library(orthopolynom)
>> l<-legendre.polynomials(4)
>> l
> [[1]]
> 1
> 
> [[2]]
> x
> 
> [[3]]
> -0.5 + 1.5*x^2
> 
> [[4]]
> -1.5*x + 2.5*x^3
> 
> [[5]]
> 0.375 - 3.75*x^2 + 4.375*x^4
> 
> But I can't figure out how to implement functions that could be
> evaluated for arbitrary 'x', from this list,
> Thanks for your help.
> 
> Ariel./
> 
> 

-- 
Dimitris Rizopoulos
Assistant Professor
Department of Biostatistics
Erasmus Medical Center

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