rombf(a,b,N,func,param)

function R = rombf(a,b,N,func,param)
%  Function to compute integrals by Romberg algorithm
%  R = rombf(a,b,N,func,param)
%  Inputs -
%    a,b   Lower and upper bound of the integral
%    N     Romberg table is N by N
%    func  Name of integrand function in a string such as
%          func='my_f'.  The calling sequence is my_f(x,param)
%    param Set of parameters to be passed to function
%  Output -
%     R    Romberg table; Entry R(N,N) is best estimate of
%          the value of the integral
h = b - a;        % This is the coarsest panel size
% Compute the first term R(1,1)
R(1,1) = h/2 * (feval(func,a,param) + feval(func,b,param));
np = 1;           % np is the number of panels
for i=2:N,
  h = h/2;          % Use panels half the previous size
  np = 2*np;        % Use twice as many panels
  sum = 0;
  for k=1:2:np-1,   % This for loop goes k=1,3,5,...,np-1
    sum = sum + feval(func, a + k*h, param);
  end
% Compute the first column entry R(i,1) 
  R(i,1) = 1/2 * R(i-1,1) + h * sum;   
  m = 1;
% Compute the other columns R(i,2), ..., R(i,i)
  for j=2:i,
    m = 4*m;
    R(i,j) = R(i,j-1) + (R(i,j-1) - R(i-1,j-1))/(m-1);
  end
end
return;