Lab for the Adams Bashforth Moulton Method

Module for the Adams-Bashforth-Moulton Method

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Adams-Bashforth-Moulton Method for O.D.E's. To approximate the solution of the initial value problem [Graphics:ab.txtgr1.gif] with [Graphics:ab.txtgr2.gif] over [Graphics:ab.txtgr3.gif] by using the predictor
[Graphics:ab.txtgr4.gif]
and the corrector
[Graphics:ab.txtgr5.gif].

[Graphics:ab.txtgr7.gif][Graphics:ab.txtgr6.gif]
 
 

Report to be handed in.

Computer Problems.

 

Exercise 1. Solve the I.V.P. [Graphics:ab.txtgr8.gif] with y(0) = 0 over [Graphics:ab.txtgr9.gif].
Use 40 subintervals of [0,10] to get your answer.
Plot the solution using 40 subintervals.
Report the last point which is the numerical approximation to (10, y(10)).

[Graphics:ab.txtgr7.gif][Graphics:ab.txtgr10.gif]

[Graphics:ab.txtgr7.gif][Graphics:ab.txtgr11.gif]

[Graphics:ab.txtgr7.gif][Graphics:ab.txtgr12.gif]

Exercise 2. Solve the I.V.P. [Graphics:ab.txtgr13.gif] with y(0) = 0 over [0.0, 10.0].
Use 100 subintervals of [0,10] to get your answer.
Plot the solution using 100 subintervals.
Report the last point which is the numerical approximation to (10, y(10)).

[Graphics:ab.txtgr7.gif][Graphics:ab.txtgr14.gif]

[Graphics:ab.txtgr7.gif][Graphics:ab.txtgr15.gif]

[Graphics:ab.txtgr7.gif][Graphics:ab.txtgr16.gif]

Remark. The value of y(10) is known to be:

[Graphics:ab.txtgr7.gif][Graphics:ab.txtgr17.gif]

Compare it with the last computed value.


For problems 3 - 5 we will use the I.V.P. [Graphics:ab.txtgr18.gif].

Exercise 3. Solve [Graphics:ab.txtgr19.gif].
Use 65 subintervals of [0,10] to get your answer.
Plot the solution using 65 subintervals.

[Graphics:ab.txtgr7.gif][Graphics:ab.txtgr20.gif]
[Graphics:ab.txtgr7.gif][Graphics:ab.txtgr21.gif]

[Graphics:ab.txtgr7.gif][Graphics:ab.txtgr22.gif]

Exercise 4. Solve [Graphics:ab.txtgr23.gif]
Use 37 subintervals of [0,10] to get your answer.
Plot the solution using 37 subintervals.

[Graphics:ab.txtgr7.gif][Graphics:ab.txtgr24.gif]

[Graphics:ab.txtgr7.gif][Graphics:ab.txtgr25.gif]

Exercise 5. Use Mathematica or techniques learned in calculus to obtain the analytic solution to the D.E.

[Graphics:ab.txtgr7.gif][Graphics:ab.txtgr26.gif]
[Graphics:ab.txtgr7.gif][Graphics:ab.txtgr27.gif]

Exercise 6. Graph the analytic solution to the D.E. found in problem 4.

[Graphics:ab.txtgr7.gif][Graphics:ab.txtgr28.gif]

[Graphics:ab.txtgr7.gif][Graphics:ab.txtgr29.gif]

Exercise 7. Read the textbook and see if you can find out something about difficulties with the step size when using a predictor-corrector method.

Exercise 8. Why does the solution in problem 4 exhibit a chaotic behavior ?

 

 

 

(c) John H. Mathews, 1998