Lagrange interpolation is well-known to be susceptible to Runge's phenomenon. This is the occurrence of large oscillations in the interpolating polynomial near the endpoints of a set of data points, when the data points origin has no oscillatory behaviour there. Runge studied the function f(x) 1 1+25x2 (3.3) on the interval [1, 1], using data points interpolated at n + 1 equidistant points, xk, going from x01 to xn = 1. 1. Write a function xeq(n) which, for a given n, returns an array of n + 1 equidistant points in [−1,1]. 2. Produce a plot illustrating the Runge phenomenon for a given set of equidistant points (i.e., for n fixed). The figure should show the functions f(x) and P(x) for x = [-1, 1], as well as the set of discrete points (xk, f(x)), k = 0,,n, used to construct P. Comment on your results. 3. Produce a second figure showing the polynomials interpolating f at n + 1 equidistant points, for a range of values of n. How does P(x) change as the number of interpolation points increases?

Algebra & Trigonometry with Analytic Geometry
13th Edition
ISBN:9781133382119
Author:Swokowski
Publisher:Swokowski
Chapter4: Polynomial And Rational Functions
Section4.3: Zeros Of Polynomials
Problem 65E
icon
Related questions
Question
Lagrange interpolation is well-known to be susceptible to Runge's phenomenon. This is the
occurrence of large oscillations in the interpolating polynomial near the endpoints of a set of data
points, when the data points origin has no oscillatory behaviour there. Runge studied the function
f(x)
1
1+25x2
(3.3)
on the interval [−1, 1], using data points interpolated at n + 1 equidistant points, xk, going from
xo 1 to xn = 1.
1. Write a function xeq(n) which, for a given n, returns an array of n + 1 equidistant points in
[−1,1].
2. Produce a plot illustrating the Runge phenomenon for a given set of equidistant points (i.e.,
for n fixed). The figure should show the functions f(x) and P(x) for x = [−1,1], as well as
the set of discrete points (xk, f(x)), k = 0,...,n, used to construct P. Comment on your
results.
3. Produce a second figure showing the polynomials interpolating f at n + 1 equidistant points,
for a range of values of n. How does P(x) change as the number of interpolation points
increases?
Transcribed Image Text:Lagrange interpolation is well-known to be susceptible to Runge's phenomenon. This is the occurrence of large oscillations in the interpolating polynomial near the endpoints of a set of data points, when the data points origin has no oscillatory behaviour there. Runge studied the function f(x) 1 1+25x2 (3.3) on the interval [−1, 1], using data points interpolated at n + 1 equidistant points, xk, going from xo 1 to xn = 1. 1. Write a function xeq(n) which, for a given n, returns an array of n + 1 equidistant points in [−1,1]. 2. Produce a plot illustrating the Runge phenomenon for a given set of equidistant points (i.e., for n fixed). The figure should show the functions f(x) and P(x) for x = [−1,1], as well as the set of discrete points (xk, f(x)), k = 0,...,n, used to construct P. Comment on your results. 3. Produce a second figure showing the polynomials interpolating f at n + 1 equidistant points, for a range of values of n. How does P(x) change as the number of interpolation points increases?
Expert Solution
steps

Step by step

Solved in 4 steps with 5 images

Blurred answer
Knowledge Booster
Bounded summation
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, advanced-math and related others by exploring similar questions and additional content below.
Recommended textbooks for you
Algebra & Trigonometry with Analytic Geometry
Algebra & Trigonometry with Analytic Geometry
Algebra
ISBN:
9781133382119
Author:
Swokowski
Publisher:
Cengage
Calculus For The Life Sciences
Calculus For The Life Sciences
Calculus
ISBN:
9780321964038
Author:
GREENWELL, Raymond N., RITCHEY, Nathan P., Lial, Margaret L.
Publisher:
Pearson Addison Wesley,
College Algebra
College Algebra
Algebra
ISBN:
9781305115545
Author:
James Stewart, Lothar Redlin, Saleem Watson
Publisher:
Cengage Learning
College Algebra (MindTap Course List)
College Algebra (MindTap Course List)
Algebra
ISBN:
9781305652231
Author:
R. David Gustafson, Jeff Hughes
Publisher:
Cengage Learning
Trigonometry (MindTap Course List)
Trigonometry (MindTap Course List)
Trigonometry
ISBN:
9781337278461
Author:
Ron Larson
Publisher:
Cengage Learning
College Algebra
College Algebra
Algebra
ISBN:
9781337282291
Author:
Ron Larson
Publisher:
Cengage Learning