Lab for Romberg Integration
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Romberg Integration for Quadrature Quadrature Rule for Numerical Integration.
To approximate the integral ![]()
by generating a table of approximations, and using
as the final answer.
The approximations
are stored in a special lower triangular matrix.
The elements
of the first column are computed using the sequential trapezoidal
rule
based on
subintervals of
;
then
is computed using Romberg's rule.
Elements of row j are
.
The algorithm is terminated early when
.
Report to be handed in.
Computer Projects.
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Project I. Construct the
Romberg table for finding
.
Exercise 1. Plot the function over the interval [0, 1.25].
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![[Graphics:rq.txtgr15.gif]](rq.txtgr15.gif)
Exercise 2. Construct the Romberg table using tol = 0.001
Exercise 3. The last entry in the table is Rj,j. Let's find it.
Exercise 4. Look at 10 digits in Rj,j.
Exercise 5. Are all 10 digits correct ? Why ?
How many digits can you guarantee based on the computations involving
rows 1-4 of the table ?
Exercise 6. Determine how to get Romberg integration to
achieve 10 digits of accuracy.
How many rows of the Romberg table do you think will be needed ?
Do it.
Report the answer with 10 digits of accuracy.
Project II. Construct the Romberg
table for finding
.
Exercise 7. Plot the function over the interval [0, 1].
![]()
![[Graphics:rq.txtgr23.gif]](rq.txtgr23.gif)
Exercise 8. Construct the Romberg table using tol = 0.001
Exercise 9. The last entry in the table is Rj,j. Let's find it.
Exercise 10. Look at 10 digits in Rj,j.
Exercise 11. Are all 10 digits correct ? Why ?
How many digits can you guarantee based on the computations involving
rows 1-4 of the table ?
Exercise 12. Determine how to get Romberg integration to
achieve 10 digits of accuracy.
How many rows of the Romberg table do you think will be needed ?
Do it.
Report the answer with 10 digits of accuracy.
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(c) John H. Mathews, 1998