How do I count how many iterations my root is in a smaller interval?
5 visualizaciones (últimos 30 días)
Mostrar comentarios más antiguos
Matthew Worker
el 11 de Nov. de 2017
Editada: Rena Berman
el 21 de Mzo. de 2018
In my code I need to display in the command line how many of the iterations my root was in the smaller interval. I am not entirely sure what this means, but I'm hoping someone does and can give me a hand to work out what I'm missing. At the moment the command line displays the same number of iterations for both the iterations to the root and how many iterations the root was in the smaller interval.
Code removed. Question has been answered.
0 comentarios
Respuesta aceptada
Mischa Kim
el 11 de Nov. de 2017
In each iteration you have two intervals, [a,c] and [c,b]. Compute the size of both intervals and use the last if-else condition in your code to increment itc.
1 comentario
Mischa Kim
el 11 de Nov. de 2017
I used
f = @(x) sqrt(x) - cos(x);
[a,b,it,itc] = WB(f,0,15,0.25,1e-5)
with (please double-check)
function [a,b,it,itc] = WB(f,a,b,w,tol)
it=0;
itc=0;
fa=f(a);
fb=f(b);
if fa*fb>0
error('Not guaranteed a root in interval [a,b]');
end
if abs(fa)<abs(fb)
fprintf('The root is probably closer to a than b\n');
else
abs(fa)>abs(fb);
fprintf('The root is probably closer to b than a\n');
end
while (b-a)/2>tol
c = (1-w)*a+w*b;
% fc = f(c); % not really needed
% if fc == 0
% return
% end
x = abs(a-c);
y = abs(c-b);
if f(a)*f(c)<0
b = c;
if x<y
itc = itc + 1;
end
else
a = c;
if y<x
itc = itc + 1;
end
end
it = it+1;
end
fprintf('Final interval: [%f, %f] with %d iterations and %d iterations where the root was in the smaller interval\n',a,b,it,itc)
end
Más respuestas (0)
Ver también
Categorías
Más información sobre Data Type Conversion en Help Center y File Exchange.
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!