Octave / bisection

## Copyright (C) 2021 Lenovo
##
## 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} =} bisection (@var{input1}, @var{input2})
##
## @seealso{}
## @end deftypefn

## Author: Lenovo <Lenovo@DESKTOP-EIHPQD9>
## Created: 2021-10-24

function F = bisection(f,a,b,e)
if (a > b || e < 0)
F = 'Неверные даннные';
return;
else
fa = f(a);
fb = f(b);
if (fa * fb < 0)
while(true)
fa = f(a);
c = (a + b) *0.5;
fc = f(c);
if (abs(fc) < e )
break;
else
if (fa * fc < 0)
b = c;
else
a = c;
endif
endif
endwhile
else
F = 'Неверные данные';
return;
endif
endif
F = c;
endfunction