-27 -36 81 onstruct it in R. 37, 65, 0,

MATLAB: An Introduction with Applications
6th Edition
ISBN:9781119256830
Author:Amos Gilat
Publisher:Amos Gilat
Chapter1: Starting With Matlab
Section: Chapter Questions
Problem 1P
icon
Related questions
Question

7

Suppose that random vector X E R' has mean u and variance-covariance matrix
42
-37
65
-37
178
-53
-27
Σ
65
-53
185
-36
-27
-36
81
For your convenience, you can construct it in R by running the following code:
Sigma <- matrix(c(42, -37, 65, 0, -37, 178, -53, -27, 65, -53, 185, -36, 0, -27, -36, 81), 4, 4)
(a)
Calculate the partial correlation of X1 and X, given X3 and X4. Store its value in variable ans_a.
(b)
Calculate the total correlation between X1 and the other elements of X. Store its value in variable ans b.
Transcribed Image Text:Suppose that random vector X E R' has mean u and variance-covariance matrix 42 -37 65 -37 178 -53 -27 Σ 65 -53 185 -36 -27 -36 81 For your convenience, you can construct it in R by running the following code: Sigma <- matrix(c(42, -37, 65, 0, -37, 178, -53, -27, 65, -53, 185, -36, 0, -27, -36, 81), 4, 4) (a) Calculate the partial correlation of X1 and X, given X3 and X4. Store its value in variable ans_a. (b) Calculate the total correlation between X1 and the other elements of X. Store its value in variable ans b.
(c)
Now, consider a principal component analysis of these variables (without scaling them).
(i)
Obtain the coefficient vectors for the first two principal components of X. Store them in vectors ans c i 1 and ans c i 2, respectively.
(ii)
How many principal components do you need to explain at least 90% of the variation in the data? Store your answer in variable ans c ii.
(iii)
How many principal components should you keep according to the Kaiser's Rule? Store your answer in variable ans_c_iii.
(iv)
Now, perform the scaled principal component analysis. Store the proportions of variation explained by each principal component in a vector ans_c_iv.
Transcribed Image Text:(c) Now, consider a principal component analysis of these variables (without scaling them). (i) Obtain the coefficient vectors for the first two principal components of X. Store them in vectors ans c i 1 and ans c i 2, respectively. (ii) How many principal components do you need to explain at least 90% of the variation in the data? Store your answer in variable ans c ii. (iii) How many principal components should you keep according to the Kaiser's Rule? Store your answer in variable ans_c_iii. (iv) Now, perform the scaled principal component analysis. Store the proportions of variation explained by each principal component in a vector ans_c_iv.
Expert Solution
steps

Step by step

Solved in 3 steps

Blurred answer
Recommended textbooks for you
MATLAB: An Introduction with Applications
MATLAB: An Introduction with Applications
Statistics
ISBN:
9781119256830
Author:
Amos Gilat
Publisher:
John Wiley & Sons Inc
Probability and Statistics for Engineering and th…
Probability and Statistics for Engineering and th…
Statistics
ISBN:
9781305251809
Author:
Jay L. Devore
Publisher:
Cengage Learning
Statistics for The Behavioral Sciences (MindTap C…
Statistics for The Behavioral Sciences (MindTap C…
Statistics
ISBN:
9781305504912
Author:
Frederick J Gravetter, Larry B. Wallnau
Publisher:
Cengage Learning
Elementary Statistics: Picturing the World (7th E…
Elementary Statistics: Picturing the World (7th E…
Statistics
ISBN:
9780134683416
Author:
Ron Larson, Betsy Farber
Publisher:
PEARSON
The Basic Practice of Statistics
The Basic Practice of Statistics
Statistics
ISBN:
9781319042578
Author:
David S. Moore, William I. Notz, Michael A. Fligner
Publisher:
W. H. Freeman
Introduction to the Practice of Statistics
Introduction to the Practice of Statistics
Statistics
ISBN:
9781319013387
Author:
David S. Moore, George P. McCabe, Bruce A. Craig
Publisher:
W. H. Freeman