Hi all,

I need to automate a process in order to prepare a  a big loop in the future
but I have a problem with the *command function*

First I fit a model with lm

>
model1<-lm(data2[,2]~data2[,1]+I(data2[,1]^2)+I(data2[,1]^3)+I(data2[,1]^4))

I extract the coefficients to build the polynomial.

coef<-as.matrix(model1$coefficients)

In the next step I need to define the polynomial to derive it. If I write
the coefficients manually (writing the numbers by hand) the deriv command
works fine!

bb<-deriv(~2847.22015 -463.06063*x+ 25.43829*x^2 -0.17896*x^3, namevec="x",
function.arg=40)

I would like to automate this step by being able to extract the coefficients
from the linear model and adding them into the polynomial (and not write
them by hand)!

 But if I build the polynomial with the function(x) command calling the *
coef* values, the numeric values are not interpreted, the command function
does not read properly the coefficients from the linear model.

>  fun<-function(x) coef[1]+coef[2]*x+coef[3]*x^2+coef[4]*x^3

> fun

function(x) coef[1]+coef[2]*x+coef[3]*x^2+coef[4]*x^3

How can i avoid to write the values of the coefficients by hand??

I need to do this many many times, this is the reason i need to be able to
automate the process and then build a loop to repeat it many times with
different outputs of a linear model!

Somebody can help me?


-- 
Noela
Grupo de Recursos Marinos y Pesquerías
Universidad de A Coruña

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