function [ c, x ] = differ_forward ( h, o, p )
%*****************************************************************************80
%
%% differ_forward() computes forward difference coefficients.
%
% Discussion:
%
% We determine coefficients C to approximate the derivative at X0
% of order O and precision P, using equally spaced forward
% differences, so that
%
% d^o f(x)/dx^o = sum ( 0 <= i <= o+p-1 ) c(i) f(x+ih) + O(h^(p))
%
% Licensing:
%
% This code is distributed under the MIT license.
%
% Modified:
%
% 12 January 2021
%
% Author:
%
% John Burkardt
%
% Input:
%
% real H, the spacing. 0 < H.
%
% integer O, the order of the derivative to be approximated.
% 1 <= O.
%
% integer P, the order of the error, as a power of H.
%
% Output:
%
% real C(O+P), the coefficients.
%
% real X(O+P), the evaluation points.
%
n = o + p;
x = ( 0 : n - 1 )' * h;
a = vand1 ( n, x );
b = zeros ( n, 1 );
b(o+1) = 1.0;
c = a \ b;
c = c * factorial ( o );
return
end