newton's method to solve nonlinear equation
1 Ansicht (letzte 30 Tage)
Ältere Kommentare anzeigen
hw prompt is below my work. please check my code. i am new to using newton's method and need some recommendations about what to do or fix. thank you.
what i did first:
x=[-3:0.01:3];
f = sin(x)-x.*cos(x);
plot(x,f);
what i did next:
x=0;
Tol = 0.0000001;
count = 0;
dx=0;
f=sin(0)-0*cos(0);
fprintf('step x dx f(x)\n')
fprintf('---- ----------- --------- ----------\n')
fprintf('%3i %12.8f %12.8f %12.8f\n',count,x,dx,f)
while (dx > Tol)
count = count + 1;
fprime = x.*sin(x);
xnew = x - (f./fprime);
dx=abs(x-xnew);
x = xnew;
f = sin(x)-x.*cos(x);
fprintf('%3i %12.8f %12.8f %12.8f\n',count,x,dx,f)
end
on the other homework problems, i received several answers, yet on this problem i received only one. did i make a mistake?
0 Kommentare
Akzeptierte Antwort
John D'Errico
am 10 Dez. 2020
Bearbeitet: John D'Errico
am 10 Dez. 2020
Is there a good reason why you initialized dx to be zero?
Do you see that immediately after that, you start a while loop. What is the codition?
while (dx > Tol)
Now, ask yourself. What was dx again when the loop started?
What is the value of Tol?
Is this true? (dx > Tol)?
Do you expect the while loop to ever allow entrance into the code inside that loop? What would happen if you wrote this code fragment?
while false
disp('The sky is falling! (sincerely, Chicken Little)')
end
How many times would you expect to see anything written to the command window?
4 Kommentare
Weitere Antworten (0)
Siehe auch
Kategorien
Mehr zu Scope Variables and Generate Names finden Sie in Help Center und File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!