
Dear R users,

Does anyone know how to write a function involving derivative?

i.e. I want to implementing Newton's method in R, so my function is something like

x<- x-y/y'

I am not sure how to write y' in my function. Can anyone help?

 

In addition, if I want to implementing newton's method several times, what code should I use?

Currently, I use the following code.

 

<-1
> for (i in 1:20){
+ x<-x-(x^3-2*x^2+3*x-5)/(3*x^2-4*x+3)}
> x
[1] 1.843734
 
However, when I typed in the following code, I would yield the same answer.
<-1
> for (i in 1:1){
+ x<-x-(x^3-2*x^2+3*x-5)/(3*x^2-4*x+3)}
> x
[1] 1.843734
 
Can anyone suggest me what the problem is?
 
Please help.
Thanks so much.
 
Debbie
_________________________________________________________________
View photos of singles in your area Click Here

au%2Fsearch%2Fsearch%2Easpx%3Fexec%3Dgo%26tp%3Dq%26gc%3D2%26tr%3D1%26lage%3D18%26uage%3D55%26cl%3D14%26sl%3D0%26dist%3D50%26po%3D1%26do%3D2%26trackingid%3D1046138%26r2s%3D1&_t=773166090&_r=Hotmail_Endtext&_m=EXT
	[[alternative HTML version deleted]]


