Needs a MATLAB code.

Exercise 2.6 solution

A = rand(3)

0.814 0.913 0.278

0.905 0.632 0.546

0.127 0.097 0.957

A(1: size(A,1) + 1:end)

ans = 0.814 0.632 0.957

Prints out the diagnol elements of the matrix A.

Suppose x is a column vector. Compute, without using loops or conditionals, the matrix A given by a_ij = {1/(x_i - x_j)^2 if i plusminus j, 1 otherwise. (One way to do this uses direct assignment to the diagonal elements of A. Using row/column style indices, this is rather tricky, but sec Exercise 2.6.) Suppose A is any matrix. What does this statement do? A(1: size(A, 1) + 1: end)