% METHOD OF FALSE POSITION ALGORITHM 2.5
%
% To find a solution to f(x) = 0 given the continuous function
% f on the interval [p0,p1], where f(p0) and f(p1) have
% opposite signs:
%
% INPUT: endpoints p0, p1; tolerance TOL;
% maximum number of iterations N0.
%
% OUTPUT: approximate solution p or
% a message that the algorithm fails.
syms('OK', 'P0', 'P1', 'X', 'Q0', 'Q1', 'TOL', 'NO', 'FLAG');
syms('NAME', 'OUP', 'I', 'P', 'Q','x','s');
TRUE = 1;
FALSE = 0;
fprintf(1,'This is the Method of False Position\n');
fprintf(1,'Input the function F(x) in terms of x\n');
fprintf(1,'For example: cos(x)\n');
s = input(' ','s');
F = inline(s,'x');
OK = FALSE;
while OK == FALSE
fprintf(1,'Input endpoints P0 < P1 on separate lines.\n');
P0 = input(' ');
P1 = input(' ');
if P0 > P1
X = P0;
P0 = P1;
P1 = X;
end
if P0 == P1
fprintf(1,'P0 cannot equal P1\n');
else
Q0 = F(P0);
Q1 = F(P1);
if Q0*Q1 > 0
fprintf(1,'F(P0) and F(P1) have the same sign.\n');
else
OK = TRUE;
end
end
end
OK = FALSE;
while OK == FALSE
fprintf(1,'Input tolerance\n');
TOL = input(' ');
if TOL <= 0
fprintf(1,'Tolerance must be positive\n');
else
OK = TRUE;
end
end
OK = FALSE;
while OK == FALSE
docsity.com
