Filter löschen
Filter löschen

Question about third-order ODE.

1 Ansicht (letzte 30 Tage)
Yusuke Nakamura
Yusuke Nakamura am 26 Apr. 2015
Kommentiert: Star Strider am 26 Apr. 2015
Q: The exact solution to the differential equation (t^2/0.357)f'''-(1/0.3)f'+f = t^0.3+5 is given in the figure below.
Starting with an initial condition f(2) = 6.2311, f'(2) = 0.1847 and f''(2) = -0.0646, Euler's method will over predict the solution when computing f(4).
From my following codes, I found out the graph is over predict with Euler's method, but I don't know how to get draw the exactly same graph as shown above. How could I plot the same graph?
function du = dfdeta(t,f)
du = [f(2); f(3); 1.19/t^2*f(2)-0.357/t^2*f(1)+0.357*t^(-1.7)+1.785/t^2];
and
[eta,f] = eulsys(@dfdeta,[2 4],[6.2311 0.1847 -0.0646],.01);
  1 Kommentar
Star Strider
Star Strider am 26 Apr. 2015
The Euler Method is an approximation. As the Wikipedia article (link) discusses, you cannot expect it to match an exact solution.

Melden Sie sich an, um zu kommentieren.

Antworten (0)

Kategorien

Mehr zu 2-D and 3-D Plots finden Sie in Help Center und File Exchange

Produkte

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by