1. (a) Factor the matrix into the form A= PT LU, where P is a permutation...
In this exercise you will work with LU factorization of an matrix A. Theory: Any matrix A can be reduced to an echelon form by using only row replacement and row interchanging operations. Row interchanging is almost always necessary for a computer realization because it reduces the round off errors in calculations - this strategy in computer calculation is called partial pivoting, which refers to selecting for a pivot the largest by absolute value entry in a column. The MATLAB...
Using MATLAB, develop an M-file to determine LU factorization of a square matrix with partial pivoting. That is, develop a function called mylu that is passed the square matrix [A] and returns the triangular matrices [L] and [U] and the permutation P. You are not to use MATLAB built-in function lu in your codes. Test your function by using it to solve a system of equations listed below in part 3. Confirm that your function is working properly by verifying...
5. (a) (5 marks) Find the LU factorization of the matrix A = 1 1 14 -1 -1 -4 21 3 where L is a unit 7 lower triangular matrix and U is an echelon form of A. (b) (5 marks) Use the LU factorization found in part (a) to solve Ax =
6. (Strang 2.7.22) Find P, L and U, such that PA = LU (ie the LU decomposition with row exchanges), where: [1 2 07 A= 2 4 11 1 1 1 Note: P must be a permutation matrix, L must be lower triangular with l's on the diagonal, and U must be upper triangular (with any values allowed on the diagonal).
06.Matrix Factorization: Problem 11 Previous Problem Problem List Next Problem (1 point) Find the LU factorization of -E 2 2 A 4 That is, write A LU where L is a lower trianqular matrix with ones on the diagonal, and U is an upper triangular matrix A Note: You can eam partial credit on this problem Preview My Answers Submit Answers You have attempted this problem 0 times
(911 (1) (a) Recall that a square matrix A has an LU decomposition if we can write it as the product A = LU of a lower triangular matrix and an upper triangular matrix. Show that the matrix 0 1 21 A= 3 4 5 (6 7 9] does not have an LU decomposition 0 0 Uji U12 U13 O 1 2 Il 21 l22 0 0 U22 U23 = 3 4 5 (131 132 133 0 0 U33 6...
LU be an LU factorization of matrix A e Fn×n computed by the Gaussian elimination Let PA with partial pivoting (GEPP). Let us denote Prove that (a) leyl 1, for all i >j S 2-1 maxij laijl You may assume P-1, i.e., in each step of the Gaussian elimination process the absolute value of the diagonal entry is already the largest among those of the entries below the diagonal entry on the same column You may prove the results with...
# 2 and # 3 2 -6 4 -4 0 -4 6 1. Define A = 8 01 . Determine, by hand, the LU factorization, of A. You may of course check your answer using appropriate technology tools. Then use your result to solve the system of equations Ax b, where b--4 2 0 5 2 2. Suppose A-6 -3 133Even though A is not square, it has an LU factorization A LU, 4 9 16 17 where L and...
4. Suppose that A Rnn is nonsingular. We can pose the problem of finding A-1 as the system of linear equations where X e R" is the unknown inverse matrix. We assume that A has LU factorization A LU (a) Explain how we can use the LU factorization of A and the ear system (4.1.1) to calculate the inverse A-1 Hint: The system (4.1.1) is a system of n × n equations and n × n unknowns. Consider the linear...
Please follow the directions and show steps. A2 use MATLAB, write down the MATLAB command you used. a. For the matrix A3 -4 7calculate the norm | 2 4 -1 8 0-1 b. For the matrix B0 0 4 calculate the norm | Bl22 by hand. Even the eigenvalues of BTB have to be calculated on paper without MATLAB and without using determinants! A2 use MATLAB, write down the MATLAB command you used. a. For the matrix A3 -4 7calculate...