## Copyright (C) 2021 silvestre
##
## This program is free software: you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation, either version 3 of the License, or
## (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program.  If not, see <https://www.gnu.org/licenses/>.

## -*- texinfo -*-
## @deftypefn {} {@var{retval} =} rectangulo (@var{input1}, @var{input2})
##
## @seealso{}
## @end deftypefn

## Author: silvestre <silvestre@LEGION>
## Created: 2021-11-16

function [int] = rectangulo (fun, a, b,n)
  sfun = typeinfo(fun);
  
  if strcmp(sfun,"string")
    f = str2func(strcat("@(x)",fun));
  else
    f = fun;
  endif
  h = (b-a)/n;
  x = a:h:b;
  int = 0;
  for k=1:n
    xm =(x(k)+x(k+1))/2;
    int = int + f(xm); 
  endfor
  int = int*h;
 endfunction

