newton.m

function [x,it,err] = newton1(x0,tol,fname,fpname)
% Newton's metod
% alt a) |f(x^k)| <= tol

it  = 0;
x   = x0;
fx  = feval(fname , x);
fpx = feval(fpname, x);
err = abs(fx);

str = '      iter    x-value   error';
disp(str)
disp( [it,x,err] )

while err > tol
  it = it+1;
  xnew = x - fx/fpx;
  x   = xnew;
  fx  = feval(fname , x);
  fpx = feval(fpname, x);
  err = abs(fx);
  disp( [it,x,err] )
end