[R] convergence

[Jim Lemon]

rach.s wrote:
> hie..
> how can i write a loop that makes algorithm keeps repeating until a solution
> is converged?do i use a for loop? i know that we can use for loop to ask for
> a number of repetitions, but how to use it to ask the algorithm to keep
> repeating until a solution is converged?

gregory.liebniz<-function(tol=0.0001) {
  pi.diff<-1
  iter<-0
  numer<-1
  last.pi<-0
  pi4<-0
  while(pi.diff > tol) {
   pi4<-pi4+numer/(2*iter+1)
   this.pi<-pi4*4
   pi.diff<-abs(this.pi-last.pi)
   last.pi<-this.pi
   iter<-iter+1
   numer<- -numer
  }
  return(this.pi)
}

What you want is probably a while loop, testing for a level of 
convergence like this simple method for calculating pi.

Jim